NCBI Conserved Domain Search

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 93.61 E-value: 9.30e-23

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQ-KLGGPVVLHCSAQ-PVTTRISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAI 106
Cdd:cd20978      1 PKFIQKPEKNVVvKGGQDVTLPCQVTgVPQPKITWLHNGKPLQGPMERATVEDGTLTIINVQPEDTGYYGCVATNEIGDI 80


                   ....*...
gi 2217283229  107 VSGPATVS 114
Cdd:cd20978     81 YTETLLHV 88

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 78.69 E-value: 1.70e-17

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  721 PEAPDRPTISTASETSVYVTWIPRANGGSPITAFKVEYKRMRTSNWLVAAEDiPPSKLSVEVRSLEPGSTYKFRVIAINH 800
Cdd:cd00063      1 PSPPTNLRVTDVTSTSVTLSWTPPEDDGGPITGYVVEYREKGSGDWKEVEVT-PGSETSYTLTGLKPGTEYEFRVRAVNG 79

                           90
                   ....*....|.
gi 2217283229  801 YGESFRSSASR 811
Cdd:cd00063     80 GGESPPSESVT 90

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 73.83 E-value: 7.39e-16

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG----LKISGVTVEDVGMYQCVADNGIG 387
Cdd:pfam07679    2 KFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGgtytLTISNVQPDDSGKYTCVATNSAG 80

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 72.95 E-value: 1.61e-15

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSAR-HLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd20957      9 PVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRvQILSEDVLVIPSVKREDKGMYQCFVRNDGDSAQATAELKL 88

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 72.45 E-value: 2.21e-15

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  723 APDRPTISTASETSVYVTWIPRANGGSPITAFKVEYKRMRTSNWLVAaEDIPPSKLSVEVRSLEPGSTYKFRVIAINHYG 802
Cdd:pfam00041    2 APSNLTVTDVTSTSLTVSWTPPPDGNGPITGYEVEYRPKNSGEPWNE-ITVPGTTTSVTLTGLKPGTEYEVRVQAVNGGG 80


                   ....*
gi 2217283229  803 ESFRS 807
Cdd:pfam00041   81 EGPPS 85

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 69.21 E-value: 3.46e-14

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYdshglitsHPSQVLRSKSRksqlsrpeglnlepvYFVLSQAGASS 484
Cdd:pfam07679    1 PKFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWF--------KDGQPLRSSDR---------------FKVTYEGGTYT 57

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:pfam07679   58 LTISNVQPDDSGKYTCVATNSAGEAEASAELTV 90

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 66.10 E-value: 3.83e-13

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   721 PEAPDRPTISTASETSVYVTWIP--RANGGSPITAFKVEYKRmRTSNWLVAAEDipPSKLSVEVRSLEPGSTYKFRVIAI 798
Cdd:smart00060    1 PSPPSNLRVTDVTSTSVTLSWEPppDDGITGYIVGYRVEYRE-EGSEWKEVNVT--PSSTSYTLTGLKPGTEYEFRVRAV 77


                    ....*.
gi 2217283229   799 NHYGES 804
Cdd:smart00060   78 NGAGEG 83

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 65.88 E-value: 4.27e-13

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217283229  314 ISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIH-PSARHLTAGNGLKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd20978      4 IQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQgPMERATVEDGTLTIINVQPEDTGYYGCVATNEIG 78

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 65.45 E-value: 8.74e-13

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  312 ASISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNGLK----ISGVTVEDVGMYQCVADNgig 387
Cdd:cd05747      4 ATILTKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQITSTEYKstfeISKVQMSDEGNYTVVVEN--- 80

                           90
                   ....*....|.
gi 2217283229  388 fmhSTGRLEIE 398
Cdd:cd05747     81 ---SEGKQEAQ 88

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 64.51 E-value: 1.10e-12

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHP---SARHLTAGNG-LKISGVTVEDVGMYQCVADN 384
Cdd:pfam13927    3 VITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSgstRSRSLSGSNStLTISNVTRSDAGTYTCVASN 78

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 64.12 E-value: 1.41e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  404 KPVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVLRSKSRKsqlsrpeglnlepvyfvlsqagaS 483
Cdd:pfam13927    1 KPVITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSN-----------------------S 57

                           90       100
                   ....*....|....*....|.
gi 2217283229  484 SLHIQAVTQEHAGKYICEAAN 504
Cdd:pfam13927   58 TLTISNVTRSDAGTYTCVASN 78

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 64.16 E-value: 1.70e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  318 LQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05728      6 ISDTEADIGSSLRWECKASGNPRPAYRWLKNGQPLASENRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTIYASAELAV 85

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 64.06 E-value: 2.02e-12

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   411 PVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGlitshpsQVLRSKSRKSqlsrpeglnlepvyfVLSQAGASSLHIQAV 490
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSPPPEVTWYKQGG-------KLLAESGRFS---------------VSRSGSTSTLTISNV 58

                            90       100
                    ....*....|....*....|....*..
gi 2217283229   491 TQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:smart00410   59 TPEDSGTYTCAATNSSGSASSGTTLTV 85

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 63.57 E-value: 2.76e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  316 KGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRL 395
Cdd:cd05725      2 KRPQNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKGRYEILDDHSLKIRKVTAGDMGSYTCVAENMVGKIEASATL 81

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 64.04 E-value: 2.81e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   30 YFTSEPLSAVQKLGGPVVLHCSAQPVTT-RISWLHNGKTLDGNLEH--VKIHQGTLTILSL-----NSSLLGYYQCLANN 101
Cdd:cd05722      3 YFLSEPSDIVAMRGGPVVLNCSAESDPPpKIEWKKDGVLLNLVSDErrQQLPNGSLLITSVvhskhNKPDEGFYQCVAQN 82

                           90
                   ....*....|....*
gi 2217283229  102 -SIGAIVSGPATVSV 115
Cdd:cd05722     83 eSLGSIVSRTARVTV 97

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 62.91 E-value: 5.00e-12

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNA-QPIHPSARHLTAGNG----LKISGVTVEDVGMYQCVADNGIGFMHSTG 393
Cdd:smart00410    2 PSVTVKEGESVTLSCEASGSPPPEVTWYKQGgKLLAESGRFSVSRSGststLTISNVTPEDSGTYTCAATNSSGSASSGT 81


                    ....
gi 2217283229   394 RLEI 397
Cdd:smart00410   82 TLTV 85

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 61.89 E-value: 1.31e-11

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  226 THSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH----LATDSVDPADSGNYSCMAGNKSGDVK 300
Cdd:pfam07679    5 QKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGgtytLTISNVQPDDSGKYTCVATNSAGEAE 83

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 60.42 E-value: 2.60e-11

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  329 VHFTCDVHGNPAPNCTWFHNAQPIHPSA---RHLTAGNG-LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd00096      1 VTLTCSASGNPPPTITWYKNGKPLPPSSrdsRRSELGNGtLTISNVTLEDSGTYTCVASNSAG 63

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 59.65 E-value: 5.05e-11

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  239 VTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLY----SHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd00096      1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSelgnGTLTISNVTLEDSGTYTCVASNSAG 63

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 60.20 E-value: 6.38e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  836 EAVSDTQIMLKWTyiPSSNNNTPIQGFYIYYRPTDSDNDSDYkrDVVEGSKQWHMIGHLQPETSYDIKMQCFNEGGESEF 915
Cdd:cd00063     10 TDVTSTSVTLSWT--PPEDDGGPITGYVVEYREKGSGDWKEV--EVTPGSETSYTLTGLKPGTEYEFRVRAVNGGGESPP 85


                   ....*...
gi 2217283229  916 SNVMICET 923
Cdd:cd00063     86 SESVTVTT 93

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 59.43 E-value: 8.42e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWydshglitSHPSQVLRSKSRKSQLsrpeglnlepvyfvLSQAGASS 484
Cdd:cd05744      1 PHFLQAPGDLEVQEGRLCRFDCKVSGLPTPDLFW--------QLNGKPVRPDSAHKML--------------VRENGRHS 58

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05744     59 LIIEPVTKRDAGIYTCIARNRAGENSFNAELVV 91

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 58.73 E-value: 1.41e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  226 THSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRL----YSHLATDSVDPADSGNYSCMAGN 294
Cdd:pfam13927    6 VSPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSlsgsNSTLTISNVTRSDAGTYTCVASN 78

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 58.57 E-value: 1.81e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   34 EPLSAVQKLGGPVVLHCSAqPV---TTRISWLHNGKTLDGNLEHVKI-HQGTLTILSLNSSLLGYYQCLANNSIGAIVSG 109
Cdd:cd05724      3 EPSDTQVAVGEMAVLECSP-PRghpEPTVSWRKDGQPLNLDNERVRIvDDGNLLIAEARKSDEGTYKCVATNMVGERESR 81


                   ....*.
gi 2217283229  110 PATVSV 115
Cdd:cd05724     82 AARLSV 87

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 58.66 E-value: 2.01e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  316 KGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARH--LTAGNG---LKISGVTVEDVGMYQCVADNGIGFMH 390
Cdd:cd05744      5 QAPGDLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSAHkmLVRENGrhsLIIEPVTKRDAGIYTCIARNRAGENS 84


                   ....*..
gi 2217283229  391 STGRLEI 397
Cdd:cd05744     85 FNAELVV 91

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 58.20 E-value: 2.95e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHpsqvlrSKSRKsqlsrpeglnlepvYFVLSQAGASS 484
Cdd:cd20951      1 PEFIIRLQSHTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDPS------SIPGK--------------YKIESEYGVHV 60

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20951     61 LHIRRVTVEDSAVYSAVAKNIHGEASSSASVVV 93

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 58.20 E-value: 3.19e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  314 ISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSArhlTAGN----------GLKISGVTVEDVGMYQCVAD 383
Cdd:cd20951      3 FIIRLQSHTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDPSS---IPGKykieseygvhVLHIRRVTVEDSAVYSAVAK 79

                           90
                   ....*....|....*
gi 2217283229  384 NGIGFMHSTGRLEIE 398
Cdd:cd20951     80 NIHGEASSSASVVVE 94

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 57.96 E-value: 3.69e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  321 QIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSAR-----HLTAGNG----LKISGVTVEDVGMYQCVADNGIGFMHS 391
Cdd:cd20956     11 QTLQPGPSVSLKCVASGNPLPQITWTLDGFPIPESPRfrvgdYVTSDGDvvsyVNISSVRVEDGGEYTCTATNDVGSVSH 90


                   ....*.
gi 2217283229  392 TGRLEI 397
Cdd:cd20956     91 SARINV 96

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 57.79 E-value: 3.86e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVAD-GDFVTLSCNASGLPVPVIRWydshglitSHPSQVLRSKSRKSQLSRpeglnlepvyfvlsqagaS 483
Cdd:cd20978      1 PKFIQKPEKNVVVKgGQDVTLPCQVTGVPQPKITW--------LHNGKPLQGPMERATVED------------------G 54

                           90       100       110
                   ....*....|....*....|....*....|....
gi 2217283229  484 SLHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20978     55 TLTIINVQPEDTGYYGCVATNEIGDIYTETLLHV 88

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 57.61 E-value: 4.74e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  232 AVLSRSPVTLECVVSGVPAPQVYWLKDGQD------IAPGSNWRRLYShLATDSVDPADSGNYSCMAGNKSGDVKYvTYM 305
Cdd:cd05729     15 ALPAANKVRLECGAGGNPMPNITWLKDGKEfkkehrIGGTKVEEKGWS-LIIERAIPRDKGKYTCIVENEYGSINH-TYD 92


                   ...
gi 2217283229  306 VNV 308
Cdd:cd05729     93 VDV 95

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 57.66 E-value: 4.75e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTW---------FHNaQPIHPSARHLTAGNG-LKISGVTVEDVGMYQCVADNGIGF 388
Cdd:cd05726      7 RDQVVALGRTVTFQCETKGNPQPAIFWqkegsqnllFPY-QPPQPSSRFSVSPTGdLTITNVQRSDVGYYICQALNVAGS 85


                   ....*....
gi 2217283229  389 MHSTGRLEI 397
Cdd:cd05726     86 ILAKAQLEV 94

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 57.17 E-value: 7.82e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAP-----GSNWRRLYSHLATDSVDPADSGNYSCMAGNKSGDVKYvTYM 305
Cdd:cd05857     14 HAVPAANTVKFRCPAAGNPTPTMRWLKNGKEFKQehrigGYKVRNQHWSLIMESVVPSDKGNYTCVVENEYGSINH-TYH 92


                   ...
gi 2217283229  306 VNV 308
Cdd:cd05857     93 LDV 95

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 56.74 E-value: 8.33e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   31 FTSEPLSAVQKLGGPVVLHCSA--QPVTTrISWLHNGKTLDGNLEHVKI-HQGTLTILSLNSSLLGYYQCLANNSigaiv 107
Cdd:cd20952      2 ILQGPQNQTVAVGGTVVLNCQAtgEPVPT-ISWLKDGVPLLGKDERITTlENGSLQIKGAEKSDTGEYTCVALNL----- 75

                           90
                   ....*....|
gi 2217283229  108 SGPATVSVAV 117
Cdd:cd20952     76 SGEATWSAVL 85

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 56.27 E-value: 9.57e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  590 TPDTYNLVWRAGKDGGLPINAYFVKYRKLDDGvgmlGSWHTVRVPGSENELHLAELEPSSLYEVLMVARSAAGEGQP 666
Cdd:pfam00041   12 TSTSLTVSWTPPPDGNGPITGYEVEYRPKNSG----EPWNEITVPGTTTSVTLTGLKPGTEYEVRVQAVNGGGEGPP 84

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 62.71 E-value: 1.05e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  590 TPDTYNLVWRAGKDGGLPINAYFVKYRKLDDGVGMLGSWHTVRVPGSENELHLAELEPSSLYEVLMVARSAAGEGQPAML 669
Cdd:COG3401     90 TATGLTTLTGSGSVGGATNTGLTSSDEVPSPAVGTATTATAVAGGAATAGTYALGAGLYGVDGANASGTTASSVAGAGVV 169

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  670 TFRTSKEKTASSKNTQASSPPVGIPKYPVVSEAANNNFGVVLTDSSRHSG------------VPEAPDRPTISTASETSV 737
Cdd:COG3401    170 VSPDTSATAAVATTSLTVTSTTLVDGGGDIEPGTTYYYRVAATDTGGESApsnevsvttpttPPSAPTGLTATADTPGSV 249

                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  738 YVTWipRANGGSPITAFKVEYKRMRTSNWLVAAEdipPSKLSVEVRSLEPGSTYKFRVIAINHYGEsfRSSASRPYQVVG 817
Cdd:COG3401    250 TLSW--DPVTESDATGYRVYRSNSGDGPFTKVAT---VTTTSYTDTGLTNGTTYYYRVTAVDAAGN--ESAPSNVVSVTT 322

                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  818 FPNrfssrPITGPHIAYTEAVSDTQIMLKWTyiPSSNNNtpIQGFYIYYRPTDSDNDSDYKRDVvegSKQWHMIGHLQPE 897
Cdd:COG3401    323 DLT-----PPAAPSGLTATAVGSSSITLSWT--ASSDAD--VTGYNVYRSTSGGGTYTKIAETV---TTTSYTDTGLTPG 390

                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  898 TSYDIKMQCFNEGG-ESEFSNVMICETKVKRVPGASEYPVkdlSTPPNSLGSGGNVGPATSPARSSDMLYLIVGCVLGVM 976
Cdd:COG3401    391 TTYYYKVTAVDAAGnESAPSEEVSATTASAASGESLTASV---DAVPLTDVAGATAAASAASNPGVSAAVLADGGDTGNA 467

                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  977 VLILMVFIAmclwKNRQQNTIQKYDPPGYLYQGSDMNGQMVDYTTLSGASQINGNVHGGFLTNGGLSSGYShlhhkvPNA 1056
Cdd:COG3401    468 VPFTTTSST----VTATTTDTTTANLSVTTGSLVGGSGASSVTNSVSVIGASAAAAVGGAPDGTPNVTGAS------PVT 537

                          490       500
                   ....*....|....*....|..
gi 2217283229 1057 VNGIVNGSLNGGLYSGHSNSLT 1078
Cdd:COG3401    538 VGASTGDVLITDLVSLTTSASS 559

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 56.02 E-value: 1.64e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217283229  237 SPVTLECVVSGVPAPQVYWLKDGQDIAP---GSNWRRLYShLATDSVDPADSGNYSCMAGNKSGDVKyVTYMVNV 308
Cdd:cd05856     20 SSVRLKCVASGNPRPDITWLKDNKPLTPpeiGENKKKKWT-LSLKNLKPEDSGKYTCHVSNRAGEIN-ATYKVDV 92

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 55.48 E-value: 2.24e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  230 ALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIApGSNWRRLY--SHLATDSVDPADSGNYSCMAGNKSGDVkYVTYMVN 307
Cdd:cd20978     10 NVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQ-GPMERATVedGTLTIINVQPEDTGYYGCVATNEIGDI-YTETLLH 87


                   .
gi 2217283229  308 V 308
Cdd:cd20978     88 V 88

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 55.03 E-value: 2.36e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  422 VTLSCNASGLPVPVIRWYDSHGLITSHPSQVLRSKSRKSqlsrpeglnlepvyfvlsqagasSLHIQAVTQEHAGKYICE 501
Cdd:cd00096      1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGNG-----------------------TLTISNVTLEDSGTYTCV 57

                           90
                   ....*....|
gi 2217283229  502 AANEHGTTQA 511
Cdd:cd00096     58 ASNSAGGSAS 67

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 55.20 E-value: 2.93e-09

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229   237 SPVTLECVVSGVPAPQVYWLKDGQD-IAPGSNWRRLYSHLAT----DSVDPADSGNYSCMAGNKSGDVK 300
Cdd:smart00410   10 ESVTLSCEASGSPPPEVTWYKQGGKlLAESGRFSVSRSGSTStltiSNVTPEDSGTYTCAATNSSGSAS 78

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 54.49 E-value: 3.27e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229   29 PYFTSEPLSAVQKLGGPVVLHCSAQPVTT-RISWLHNGKTLDGN---LEHVKIHQGTLTILSLNSSLLGYYQCLANN 101
Cdd:pfam13927    2 PVITVSPSSVTVREGETVTLTCEATGSPPpTITWYKNGEPISSGstrSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

First C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409474 Cd Length: 92 Bit Score: 55.10 E-value: 3.81e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  238 PVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYS--------HLATDSVDpaDSGNYSCMAGNKSGDV 299
Cdd:cd05893     17 PVTFTCRVAGNPKPKIYWFKDGKQISPKSDHYTIQRdldgtcslHTTASTLD--DDGNYTIMAANPQGRI 84

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 54.04 E-value: 7.08e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  577 PDAPIILSPPQThTPDTYNLVWRAGKDGGLPINAYFVKYRKLDDGvgmlgSWHTVRV-PGSENELHLAELEPSSLYEVLM 655
Cdd:cd00063      1 PSPPTNLRVTDV-TSTSVTLSWTPPEDDGGPITGYVVEYREKGSG-----DWKEVEVtPGSETSYTLTGLKPGTEYEFRV 74

                           90
                   ....*....|....*....
gi 2217283229  656 VARSAAGEGQPAM-LTFRT 673
Cdd:cd00063     75 RAVNGGGESPPSEsVTVTT 93

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 53.79 E-value: 8.20e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDI---APGSNWRRLYSHLATDSVDPADSGNYSCMAGNKSGDV 299
Cdd:cd20976     11 LEAVEGQDFVAQCSARGKPVPRITWIRNAQPLqyaADRSTCEAGVGELHIQDVLPEDHGTYTCLAKNAAGQV 82

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 53.96 E-value: 8.79e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  227 HSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSN------WRRLYSH-LATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd20951      6 RLQSHTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDPSSIpgkykiESEYGVHvLHIRRVTVEDSAVYSAVAKNIHG 83

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 53.65 E-value: 1.04e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  314 ISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTA-GNG-LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd20952      2 ILQGPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTlENGsLQIKGAEKSDTGEYTCVALNLSG 77

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 53.78 E-value: 1.13e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLysHLATD-------SVDPADSGNYSCMAGNKSGDV 299
Cdd:cd05763      9 ITIRAGSTARLECAATGHPTPQIAWQKDGGTDFPAARERRM--HVMPEddvffivDVKIEDTGVYSCTAQNSAGSI 82

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 53.02 E-value: 1.32e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG-LKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05745      2 GQTVDFLCEAQGYPQPVIAWTKGGSQLSVDRRHLVLSSGtLRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 52.80 E-value: 1.92e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  233 VLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGS----NWRRLyshLATDSVDPADSGNYSCMAGNKSGDVKYvTYMVNV 308
Cdd:cd05731      7 VLRGGVLLLECIAEGLPTPDIRWIKLGGELPKGRtkfeNFNKT---LKIENVSEADSGEYQCTASNTMGSARH-TISVTV 82

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 52.95 E-value: 2.17e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  237 SPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWR---------RLYSHLATDSVDPADSGNYSCMAGNKSGDVKYVTyMVN 307
Cdd:cd20956     17 PSVSLKCVASGNPLPQITWTLDGFPIPESPRFRvgdyvtsdgDVVSYVNISSVRVEDGGEYTCTATNDVGSVSHSA-RIN 95


                   .
gi 2217283229  308 V 308
Cdd:cd20956     96 V 96

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 52.40 E-value: 2.68e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  233 VLSRSPVTLECVVS-GVPAPQVYWLKDGQDIAPGSNWRRLYS--HLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05724      9 VAVGEMAVLECSPPrGHPEPTVSWRKDGQPLNLDNERVRIVDdgNLLIAEARKSDEGTYKCVATNMVG 76

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 52.25 E-value: 3.65e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG---LKISGVTVEDVGMYQCVADNGIGFM 389
Cdd:cd20976      3 SFSSVPKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAGvgeLHIQDVLPEDHGTYTCLAKNAAGQV 82


                   ....*...
gi 2217283229  390 HSTGRLEI 397
Cdd:cd20976     83 SCSAWVTV 90

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 52.07 E-value: 3.85e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHP---SARHLTAGNGLKISGVTVEDVGMYQCVADNGIGF 388
Cdd:cd04978      7 PSLVLSPGETGELICEAEGNPQPTITWRLNGVPIEPapeDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHGY 79

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 51.78 E-value: 3.90e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  411 PVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGlitSHPSQVLRSKSrksqlsrpeglnlEPVyfvlsqagassLHIQAV 490
Cdd:cd04968      8 PADTYALKGQTVTLECFALGNPVPQIKWRKVDG---SPSSQWEITTS-------------EPV-----------LEIPNV 60

                           90       100
                   ....*....|....*....|....*..
gi 2217283229  491 TQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd04968     61 QFEDEGTYECEAENSRGKDTVQGRIIV 87

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 51.78 E-value: 4.34e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRL 395
Cdd:cd04968     16 GQTVTLECFALGNPVPQIKWRKVDGSPSSQWEITTSEPVLEIPNVQFEDEGTYECEAENSRGKDTVQGRI 85

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 51.85 E-value: 4.37e-08

                            10        20        30        40        50        60        70
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229   836 EAVSDTQIMLKWTyIPSSNNNTpiqGFYIYYRPTDSDNDSDYKRDVVEGSKQWHMIGHLQPETSYDIKMQCFNEGGES 913
Cdd:smart00060   10 TDVTSTSVTLSWE-PPPDDGIT---GYIVGYRVEYREEGSEWKEVNVTPSSTSYTLTGLKPGTEYEFRVRAVNGAGEG 83

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the human APEG-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409567 Cd Length: 91 Bit Score: 51.70 E-value: 5.34e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  318 LQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLT--AGNG---LKISGVTVEDVGMYQCVADNGIGFMHST 392
Cdd:cd20975      7 LMDQSVREGQDVIMSIRVQGEPKPVVSWLRNRQPVRPDQRRFAeeAEGGlcrLRILAAERGDAGFYTCKAVNEYGARQCE 86


                   ....*
gi 2217283229  393 GRLEI 397
Cdd:cd20975     87 ARLEV 91

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 51.45 E-value: 6.93e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  317 GLQDQIVSL-GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGN-----GLKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05891      6 GLPDVVTIMeGKTLNLTCTVFGNPDPEVIWFKNDQDIELSEHYSVKLEqgkyaSLTIKGVTSEDSGKYSINVKNKYG 82

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 51.37 E-value: 7.96e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  418 DGDFVTLSCNASGLPVPVIRWYDSHGLITShpsqvlrskSRKSqlsrPEGlNLEpvyfVLSQAGASSLHIQAVTQEHAGK 497
Cdd:cd05732     15 ELEQITLTCEAEGDPIPEITWRRATRGISF---------EEGD----LDG-RIV----VRGHARVSSLTLKDVQLTDAGR 76

                           90
                   ....*....|...
gi 2217283229  498 YICEAANEHGTTQ 510
Cdd:cd05732     77 YDCEASNRIGGDQ 89

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 51.10 E-value: 8.70e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWydshgLITSHPSQVLRSKSRksqlsrpeglnlepvyfvlSQAGASS 484
Cdd:cd20976      2 PSFSSVPKDLEAVEGQDFVAQCSARGKPVPRITW-----IRNAQPLQYAADRST-------------------CEAGVGE 57

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20976     58 LHIQDVLPEDHGTYTCLAKNAAGQVSCSAWVTV 90

First C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409474 Cd Length: 92 Bit Score: 50.87 E-value: 1.02e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGN------GLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05893     15 GMPVTFTCRVAGNPKPKIYWFKDGKQISPKSDHYTIQRdldgtcSLHTTASTLDDDGNYTIMAANPQGRISCTGRLMV 92

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 50.27 E-value: 1.40e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  329 VHFTCDVHGNPAPNCTWFHNAQPIHPSAR-HLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05723     15 IVFECEVTGKPTPTVKWVKNGDVVIPSDYfKIVKEHNLQVLGLVKSDEGFYQCIAENDVGNAQASAQLII 84

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 50.32 E-value: 1.59e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  230 ALAVLSRSpVTLECVVSGVPAPQVYWLKDGQDIAPGSN---WRRLYSHLATDSVDPADSGNYSCMAGNKSGD 298
Cdd:cd05730     13 ATANLGQS-VTLACDADGFPEPTMTWTKDGEPIESGEEkysFNEDGSEMTILDVDKLDEAEYTCIAENKAGE 83

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 49.88 E-value: 1.88e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  315 SKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG-----LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd20973      1 IQTLRDKEVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEdglcsLIISDVCGDDSGKYTCKAVNSLG 78

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 50.02 E-value: 2.12e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  312 ASISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNGLKISGVTVEDVGMYQCVADN 384
Cdd:cd05851      2 ADINVKFKDTYALKGQNVTLECFALGNPVPVIRWRKILEPMPATAEISMSGAVLKIFNIQPEDEGTYECEAEN 74

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 49.32 E-value: 2.76e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  408 ITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVLRSKsrksqlsrpeglnlepvyfvlsqagasSLHI 487
Cdd:cd05725      1 VKRPQNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKGRYEILDDH---------------------------SLKI 53

                           90       100       110
                   ....*....|....*....|....*....|
gi 2217283229  488 QAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05725     54 RKVTAGDMGSYTCVAENMVGKIEASATLTV 83

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 49.34 E-value: 2.87e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  826 PITGPHIaytEAVSDTQIMLKWTyiPSSNNNTPIQGFYIYYRPTDSDNDSdyKRDVVEGSKQWHMIGHLQPETSYDIKMQ 905
Cdd:pfam00041    2 APSNLTV---TDVTSTSLTVSWT--PPPDGNGPITGYEVEYRPKNSGEPW--NEITVPGTTTSVTLTGLKPGTEYEVRVQ 74

                           90
                   ....*....|.
gi 2217283229  906 CFNEGGESEFS 916
Cdd:pfam00041   75 AVNGGGEGPPS 85

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 49.04 E-value: 3.65e-07

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229    41 KLGGPVVLHCSA-QPVTTRISWLHNGKTLDGNLEHVKI----HQGTLTILSLNSSLLGYYQCLANNSIGaIVSGPATVSV 115
Cdd:smart00410    7 KEGESVTLSCEAsGSPPPEVTWYKQGGKLLAESGRFSVsrsgSTSTLTISNVTPEDSGTYTCAATNSSG-SASSGTTLTV 85

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 49.11 E-value: 3.99e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH-----LATDSVDPADSGNYSCMAGNKSGD 298
Cdd:cd20973      7 KEVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEdglcsLIISDVCGDDSGKYTCKAVNSLGE 79

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 49.18 E-value: 4.62e-07

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  240 TLECVVSGVPAPQVYWLKDGQDIAPG-SNWRRLY---SHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05736     19 SLRCHAEGIPLPRVQWLKNGMDINPKlSKQLTLIangSELHISNVRYEDTGAYTCIAKNEGG 80

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 49.23 E-value: 4.74e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGlitSHPSQVlrsksrKSQLSRPeGLNLEPvyfvlsqagASS 484
Cdd:cd20954      2 PRWIVEPVDANVAAGQDVMLHCQADGFPTPTVTWKKATG---STPGEY------KDLLYDP-NVRILP---------NGT 62

                           90       100
                   ....*....|....*....|....
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGT 508
Cdd:cd20954     63 LVFGHVQKENEGHYLCEAKNGIGS 86

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 48.73 E-value: 5.31e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPG-----SNWRRLYSHLATDSVdPADSGNYSCMAGNKSG 297
Cdd:cd20972      9 RSQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNSpdiqiHQEGDLHSLIIAEAF-EEDTGRYSCLATNSVG 81

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 48.38 E-value: 5.45e-07

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   577 PDAPIILSPPQThTPDTYNLVWRAGKDGGlpINAYFVKYRKLDDGVGmlGSWHTVRVPGSENELHLAELEPSSLYEVLMV 656
Cdd:smart00060    1 PSPPSNLRVTDV-TSTSVTLSWEPPPDDG--ITGYIVGYRVEYREEG--SEWKEVNVTPSSTSYTLTGLKPGTEYEFRVR 75


                    ....*...
gi 2217283229   657 ARSAAGEG 664
Cdd:smart00060   76 AVNGAGEG 83

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 48.48 E-value: 6.05e-07

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  323 VSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGN----GLKISGVTVEDVGMYQCVADN 384
Cdd:cd20949     11 VKEGQSATILCEVKGEPQPNVTWHFNGQPISASVADMSKYRiladGLLINKVTQDDTGEYTCRAYQ 76

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 48.61 E-value: 6.12e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  322 IVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSAR-HLTAGNGLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd04969     13 LAAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRiCILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANSTGSLSV 89

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 48.66 E-value: 6.33e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNA-QPIHPSARHLTAGNG--LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd20970      4 STPQPSFTVTAREGENATFMCRAEGSPEPEISWTRNGnLIIEFNTRYIVRENGttLTIRNIRRSDMGIYLCIASNGVP 81

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 48.26 E-value: 7.79e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLY----SH-LATDSVDPADSGNYSCMAGNKSGDV 299
Cdd:cd05744      8 GDLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSAHKMLVrengRHsLIIEPVTKRDAGIYTCIARNRAGEN 83

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 48.50 E-value: 8.43e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIA----PGS--NWRRLYSHLATDSVDPADSGNYSCMAGNKSGD-VKY 301
Cdd:cd20974      8 QSVVVLEGSTATFEAHVSGKPVPEVSWFRDGQVIStstlPGVqiSFSDGRAKLSIPAVTKANSGRYSLTATNGSGQaTST 87


                   ....*
gi 2217283229  302 VTYMV 306
Cdd:cd20974     88 AELLV 92

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 47.21 E-value: 1.39e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  228 SQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGsnwRRLYSH----LATDSVDPADSGNYSCMAGNKSGDVKYvT 303
Cdd:cd05876      2 SSSLVALRGQSLVLECIAEGLPTPTVKWLRPSGPLPPD---RVKYQNhnktLQLLNVGESDDGEYVCLAENSLGSARH-A 77


                   ....*
gi 2217283229  304 YMVNV 308
Cdd:cd05876     78 YYVTV 82

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 47.49 E-value: 1.46e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  239 VTLECVVSGVPAP-QVYWLKDGQDIAP--GSNWRRL---YSHLATDSVDPADSGNYSCMAGNKSGDVKYVT 303
Cdd:cd20959     20 AQLHCGVPGGDLPlNIRWTLDGQPISDdlGITVSRLgrrSSILSIDSLEASHAGNYTCHARNSAGSASYTA 90

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 47.58 E-value: 1.60e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYdshglitshpsqvlrsksrksqlsrPEGLNLE--PVYFVLSQAGA 482
Cdd:cd20972      2 PQFIQKLRSQEVAEGSKVRLECRVTGNPTPVVRWF-------------------------CEGKELQnsPDIQIHQEGDL 56

                           90       100       110
                   ....*....|....*....|....*....|....*
gi 2217283229  483 SSLHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20972     57 HSLIIAEAFEEDTGRYSCLATNSVGSDTTSAEIFV 91

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 47.24 E-value: 1.78e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   28 APYFTSEP--LSAVQklGGPVVLHCSAQ--PVTtRISWLHNGKTLDGNLEHVKIHQGT--LTILSLNSSLLGYYQCLANN 101
Cdd:cd20976      1 APSFSSVPkdLEAVE--GQDFVAQCSARgkPVP-RITWIRNAQPLQYAADRSTCEAGVgeLHIQDVLPEDHGTYTCLAKN 77

                           90
                   ....*....|....
gi 2217283229  102 SIGaIVSGPATVSV 115
Cdd:cd20976     78 AAG-QVSCSAWVTV 90

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 47.21 E-value: 1.91e-06

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  242 ECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSHLATDSVDPADSGNYSCMAGNKSGDV 299
Cdd:cd05728     20 ECKASGNPRPAYRWLKNGQPLASENRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTI 77

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 47.26 E-value: 2.22e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  408 ITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVLRSKSRksqlsrpeglnlepvyFVLSQAGasSLHI 487
Cdd:cd05726      3 VVKPRDQVVALGRTVTFQCETKGNPQPAIFWQKEGSQNLLFPYQPPQPSSR----------------FSVSPTG--DLTI 64

                           90       100       110
                   ....*....|....*....|....*....|
gi 2217283229  488 QAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05726     65 TNVQRSDVGYYICQALNVAGSILAKAQLEV 94

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 46.02 E-value: 2.84e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  329 VHFTCDVHGNPAPNCTWFHNAQPIHPSAR-HLTAGNGLKISGVTVEDVGMYQCVADNGIGF 388
Cdd:cd05746      1 VQIPCSAQGDPEPTITWNKDGVQVTESGKfHISPEGYLAIRDVGVADQGRYECVARNTIGY 61

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 46.78 E-value: 3.49e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQKLGGPVVLHCSAQ--PVTTrISWLHNGKTLDGNLEHVKIHQ-----GTLTILSL-----NSSLLGYYQ 96
Cdd:cd07693      1 PRIVEHPSDLIVSKGDPATLNCKAEgrPTPT-IQWLKNGQPLETDKDDPRSHRivlpsGSLFFLRVvhgrkGRSDEGVYV 79

                           90       100
                   ....*....|....*....|
gi 2217283229   97 CLANNSIGAIVSGPATVSVA 116
Cdd:cd07693     80 CVAHNSLGEAVSRNASLEVA 99

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 46.49 E-value: 3.55e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  321 QIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHP--SARHLTAGNG--LKISGVTVEDVGMYQCVADNGIGFMHSTGRLE 396
Cdd:cd05736     10 QAKEPGVEASLRCHAEGIPLPRVQWLKNGMDINPklSKQLTLIANGseLHISNVRYEDTGAYTCIAKNEGGVDEDISSLF 89


                   ...
gi 2217283229  397 IEN 399
Cdd:cd05736     90 VED 92

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 46.47 E-value: 3.82e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQKLGG---PVVLHCSAQ--PVTTrISWLHNGKTLDGNLEH-VKIHQGTLTILSLNSSL-LGYYQCLANN 101
Cdd:cd05848      2 PVFVQEPDDAIFPTDSdekKVILNCEARgnPVPT-YRWLRNGTEIDTESDYrYSLIDGNLIISNPSEVKdSGRYQCLATN 80

                           90
                   ....*....|....*
gi 2217283229  102 SIGAIVSGPATVSVA 116
Cdd:cd05848     81 SIGSILSREALLQFA 95

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 46.16 E-value: 4.06e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARH----LTAGNGLKISGVTVEDVGMYQCVADNGIGF 388
Cdd:cd05738      1 IIDMGPQLKVVEKARTATMLCAASGNPDPEISWFKDFLPVDTATSNgrikQLRSGALQIENSEESDQGKYECVATNSAGT 80


                   ...
gi 2217283229  389 MHS 391
Cdd:cd05738     81 RYS 83

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 46.44 E-value: 4.32e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGN-----GLKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05729     19 ANKVRLECGAGGNPMPNITWLKDGKEFKKEHRIGGTKVeekgwSLIIERAIPRDKGKYTCIVENEYGSINHTYDVDV 95

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 45.40 E-value: 5.03e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229   46 VVLHCSAQPV-TTRISWLHNGKTLDGNLE---HVKIHQGTLTILSLNSSLLGYYQCLANNSIGAIVS 108
Cdd:cd00096      1 VTLTCSASGNpPPTITWYKNGKPLPPSSRdsrRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSAS 67

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 45.40 E-value: 5.08e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  141 CRVpESNPKAEVRYKIRGKWLEHST--ENYLILPSGNLQILNVSLEDKGSYKCAAYNPVTHQ 200
Cdd:cd00096      5 CSA-SGNPPPTITWYKNGKPLPPSSrdSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGS 65

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 45.65 E-value: 5.39e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  410 APVSAKVADGDFVTLSCNAS-GLPVPVIRWYDSHGLITsHPSQVLRSKSRKSQlsrpeglnlepvyfvlsqagaSSLHIQ 488
Cdd:pfam00047    2 APPTVTVLEGDSATLTCSAStGSPGPDVTWSKEGGTLI-ESLKVKHDNGRTTQ---------------------SSLLIS 59

                           90       100
                   ....*....|....*....|....*..
gi 2217283229  489 AVTQEHAGKYICEAANEHGTTQAEASL 515
Cdd:pfam00047   60 NVTKEDAGTYTCVVNNPGGSATLSTSL 86

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 45.96 E-value: 5.98e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  222 ILHPTHSQALAVLSRSPVTLECVVSGVPAPQVYWLKDG---QDIAPGSNWRRLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd20970      3 ISTPQPSFTVTAREGENATFMCRAEGSPEPEISWTRNGnliIEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGVP 81

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 45.86 E-value: 5.99e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  320 DQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARH--LTAGNG---LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd20990      9 DLTVQEGKLCRMDCKVSGLPTPDLSWQLDGKPIRPDSAHkmLVRENGvhsLIIEPVTSRDAGIYTCIATNRAG 81

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 45.53 E-value: 6.81e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVlrsksrksqlsrpeglnlepvyfVLSQ--AGA 482
Cdd:cd05892      1 PMFIQKPQNKKVLEGDPVRLECQISAIPPPQIFWKKNNEMLQYNTDRI-----------------------SLYQdnCGR 57

                           90       100       110
                   ....*....|....*....|....*....|....*
gi 2217283229  483 SSLHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05892     58 ICLLIQNANKKDAGWYTVSAVNEAGVVSCNARLDV 92

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 45.66 E-value: 8.02e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  312 ASISKGLQDQIVSL-GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARH---LTAGN--GLKISGVTVEDVGMYQCVADNG 385
Cdd:cd05737      1 ARVLGGLPDVVTIMeGKTLNLTCNVWGDPPPEVSWLKNDQALAFLDHCnlkVEAGRtvYFTINGVSSEDSGKYGLVVKNK 80


                   ..
gi 2217283229  386 IG 387
Cdd:cd05737     81 YG 82

Phage-related protein, tail protein J [Mobilome: prophages, transposons];

Pssm-ID: 443767 [Multi-domain] Cd Length: 978 Bit Score: 50.33 E-value: 8.31e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  696 YPVVSEAANNNFGVVLT------------DSSRHSGVPEAPDRPTISTA----------SETSVYVTWIPRANGgspiTA 753
Cdd:COG4733    491 FRVVSIEENEDGTYTITavqhapekyaaiDAGAFDDVPPQWPPVNVTTSeslsvvaqgtAVTTLTVSWDAPAGA----VA 566

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  754 FKVEYKRmRTSNWLVAAEdipPSKLSVEVRSLEPGsTYKFRVIAINHYGESFRSSASRPYQVVGfpnrfssRPITGPHIA 833
Cdd:COG4733    567 YEVEWRR-DDGNWVSVPR---TSGTSFEVPGIYAG-DYEVRVRAINALGVSSAWAASSETTVTG-------KTAPPPAPT 634

                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  834 YTEAVS-DTQIMLKWTYIPssnnNTPIQGFYIYYRPTDSDNDSDYKRDVVEGSkQWHMIGhLQPETSY 900
Cdd:COG4733    635 GLTATGgLGGITLSWSFPV----DADTLRTEIRYSTTGDWASATVAQALYPGN-TYTLAG-LKAGQTY 696

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 45.24 E-value: 1.26e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDShglitshpSQVLRSKSRKSQlSRPEGLNLEPVYFVLSQAGASS 484
Cdd:cd07693      1 PRIVEHPSDLIVSKGDPATLNCKAEGRPTPTIQWLKN--------GQPLETDKDDPR-SHRIVLPSGSLFFLRVVHGRKG 71

                           90       100       110
                   ....*....|....*....|....*....|....
gi 2217283229  485 lhiqavtQEHAGKYICEAANEHGT-TQAEASLMV 517
Cdd:cd07693     72 -------RSDEGVYVCVAHNSLGEaVSRNASLEV 98

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 45.24 E-value: 1.29e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  308 VLEHASiskglqDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPI-----HPSARHLTAGNG----LKISG--VTVEDVG 376
Cdd:cd07693      3 IVEHPS------DLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLetdkdDPRSHRIVLPSGslffLRVVHgrKGRSDEG 76

                           90
                   ....*....|.
gi 2217283229  377 MYQCVADNGIG 387
Cdd:cd07693     77 VYVCVAHNSLG 87

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 44.94 E-value: 1.33e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITshPSQvlrsksrksqlsrPEGLNLepvyfvlsQAGASS 484
Cdd:cd05736      1 PVIRVYPEFQAKEPGVEASLRCHAEGIPLPRVQWLKNGMDIN--PKL-------------SKQLTL--------IANGSE 57

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05736     58 LHISNVRYEDTGAYTCIAKNEGGVDEDISSLFV 90

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 44.88 E-value: 1.33e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  318 LQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG----LKISGVTVEDVGMYQCVADNGIGFMHSTG 393
Cdd:cd20972      8 LRSQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNSPDIQIHQEGdlhsLIIAEAFEEDTGRYSCLATNSVGSDTTSA 87


                   ....
gi 2217283229  394 RLEI 397
Cdd:cd20972     88 EIFV 91

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 44.50 E-value: 1.72e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  241 LECVVSGVPAPQVYWLKDGQDIAPGSNWR-----RLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05737     21 LTCNVWGDPPPEVSWLKNDQALAFLDHCNlkveaGRTVYFTINGVSSEDSGKYGLVVKNKYG 82

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the human APEG-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409567 Cd Length: 91 Bit Score: 44.77 E-value: 1.73e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYdshglitshpsqvlrsksRKSQLSRPEglnlEPVYFVLSQAGASS 484
Cdd:cd20975      1 PTFKVSLMDQSVREGQDVIMSIRVQGEPKPVVSWL------------------RNRQPVRPD----QRRFAEEAEGGLCR 58

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20975     59 LRILAAERGDAGFYTCKAVNEYGARQCEARLEV 91

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 2 (NCAM-2); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule NCAM-2 (also known as OCAM/mamFas II and RNCAM). NCAM-2 is organized similarly to NCAM, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143278 [Multi-domain] Cd Length: 98 Bit Score: 44.58 E-value: 1.81e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  418 DGDFVTLSCNASGLPVPVIRWYDSHGLITShpsqvlrSKSRKSQLSRPEglnlepvyfVLSQAGASSLHIQAVTQEHAGK 497
Cdd:cd05870     15 ENGAATLSCKAEGEPIPEITWKRASDGHTF-------SEGDKSPDGRIE---------VKGQHGESSLHIKDVKLSDSGR 78

                           90
                   ....*....|...
gi 2217283229  498 YICEAANEHGTTQ 510
Cdd:cd05870     79 YDCEAASRIGGHQ 91

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 43.92 E-value: 1.88e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  236 RSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNwrrlyshLATDSVDPADSGNYSCMAGNKSGDVKY 301
Cdd:pfam13895   14 GEPVTLTCSAPGNPPPSYTWYKDGSAISSSPN-------FFTLSVSAEDSGTYTCVARNGRGGKVS 72

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 44.16 E-value: 1.94e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  333 CDVHGNPAPNCTWFHNAQPIHPSAR--HLTAGNgLKISGVTVEDVGMYQCVADNGIGFMHS 391
Cdd:cd20968     21 CTTMGNPKPSVSWIKGDDLIKENNRiaVLESGS-LRIHNVQKEDAGQYRCVAKNSLGIAYS 80

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 43.92 E-value: 2.04e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIaPGSNWRRLYSH-LATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05725      5 QNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGEL-PKGRYEILDDHsLKIRKVTAGDMGSYTCVAENMVG 73

Immunoglobulin-like Ig0 domain of basigin-1 (BSG1) and similar proteins; The members here are composed of the immunoglobulin (Ig) domain of the collagenase stimulatory factor, basigin-1 (BSG1; also known as Cluster of Differentiation 147 (CD147) and Extracellular Matrix Metalloproteinase Inducer (EMMPRIN)) and similar proteins. CD147 is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily. It is expressed in nearly all cells including platelets and fibroblasts and is involved in inflammatory diseases, and cancer progression. CD147 is highly expressed in several cancers and used as a prognostic marker. The two primary isoforms of CD147 that are related to cancer progression have been identified: CD147 Ig1-Ig2 (also called Basigin-2) that is ubiquitously expressed in most tissues and CD147 Ig0-Ig1-Ig2 (also called Basigin-1) that is retinal specific and implicated in retinoblastoma. Studies showed that CD147 Ig0 domain is a potent stimulator of interleukin-6 and suggest that the CD147 Ig0 dimer is the functional unit required for activity.

Pssm-ID: 409534 Cd Length: 116 Bit Score: 44.95 E-value: 2.52e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  408 ITAPVSAKVADGDFVTLSCNASGLPVPVIRWYdshgLITSHPSQVLrsksrkSQL---SRPEGLNLEPVYfvlSQAGASS 484
Cdd:cd20940      4 IKSPLSQQRLVGDSVELHCEAVGSPIPEIQWW----FEGQEPNEIC------SQLwdgARLDRVHINATY---HQHATST 70

                           90       100
                   ....*....|....*....|.
gi 2217283229  485 LHIQAVTQEHAGKYICEAANE 505
Cdd:cd20940     71 ISIDNLTEEDTGTYECRASND 91

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 44.16 E-value: 2.55e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  324 SLGATVHFTCDVHGNPAPNCTWFHNAQPIH--PSARHLTAGNGLKISG-VTVEDVGMYQCVADNGIGFMHST 392
Cdd:cd04967     17 SDEKKVALNCRARANPVPSYRWLMNGTEIDleSDYRYSLVDGTLVISNpSKAKDAGHYQCLATNTVGSVLSR 88

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 43.72 E-value: 2.59e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  239 VTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH-LATDSVDPADSGNYSCMAGNKSGDVK 300
Cdd:cd05723     15 IVFECEVTGKPTPTVKWVKNGDVVIPSDYFKIVKEHnLQVLGLVKSDEGFYQCIAENDVGNAQ 77

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 44.07 E-value: 2.66e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  323 VSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSAR---------HLTagngLKISGVTVEDVGMYQCVADNGIGFMHSTG 393
Cdd:cd05857     16 VPAANTVKFRCPAAGNPTPTMRWLKNGKEFKQEHRiggykvrnqHWS----LIMESVVPSDKGNYTCVVENEYGSINHTY 91


                   ....
gi 2217283229  394 RLEI 397
Cdd:cd05857     92 HLDV 95

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 44.01 E-value: 2.71e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  228 SQALAVlSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRR--------LYSHLATDSVDPADSGNYSCMAGNKS 296
Cdd:cd05722      9 SDIVAM-RGGPVVLNCSAESDPPPKIEWKKDGVLLNLVSDERRqqlpngslLITSVVHSKHNKPDEGFYQCVAQNES 84

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 43.88 E-value: 2.78e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  226 THSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWR----RLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05747      8 TKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQitstEYKSTFEISKVQMSDEGNYTVVVENSEG 83

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 43.88 E-value: 2.92e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  407 IITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITShpsqvlrskSRKSQLSRPEglnlepvYfvlsqagASSLH 486
Cdd:cd05747      6 ILTKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVS---------SQRHQITSTE-------Y-------KSTFE 62

                           90       100
                   ....*....|....*....|....*....
gi 2217283229  487 IQAVTQEHAGKYICEAANEHGTTQAEASL 515
Cdd:cd05747     63 ISKVQMSDEGNYTVVVENSEGKQEAQFTL 91

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 43.94 E-value: 2.94e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  241 LECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH-----LATDSVDPADSGNYSCMAGNKSGDVKYVTYMV 306
Cdd:cd20990     20 MDCKVSGLPTPDLSWQLDGKPIRPDSAHKMLVREngvhsLIIEPVTSRDAGIYTCIATNRAGQNSFNLELV 90

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for FGFs. FGFR2 is required for male sex determination. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409444 Cd Length: 105 Bit Score: 44.18 E-value: 2.99e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  320 DQIVSLGATVHFTCDVHGNPAPNCTWFHN--------AQPIHPSARHL-TAGNG--------LKISGVTVEDVGMYQCVA 382
Cdd:cd05858     10 NTSVVVGTDAEFVCKVYSDAQPHIQWLKHvekngskyGPDGLPYVEVLkTAGVNttdkeievLYLRNVTFEDAGEYTCLA 89

                           90
                   ....*....|....*
gi 2217283229  383 DNGIGFMHSTGRLEI 397
Cdd:cd05858     90 GNSIGISHHSAWLTV 104

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 44.02 E-value: 3.19e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  319 QDQIvsLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG---------LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05734     11 QDGI--YGKAVVLNCSADGYPPPTIVWKHSKGSGVPQFQHIVPLNGriqllsngsLLIKHVLEEDSGYYLCKVSNDVG 86

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 43.65 E-value: 3.20e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  223 LHPTHSQALAVLSRspVTLEC-VVSGVPAPQVYWLKDGQDIAPGSNWR------RLYSHLATDSVDPADSGNYSCMAGNK 295
Cdd:cd05750      3 LKEMKSQTVQEGSK--LVLKCeATSENPSPRYRWFKDGKELNRKRPKNikirnkKKNSELQINKAKLEDSGEYTCVVENI 80


                   ..
gi 2217283229  296 SG 297
Cdd:cd05750     81 LG 82

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 43.77 E-value: 3.25e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  220 VHILHPTHSqalavlSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRrlYSHLATDSV--DPA---DSGNYSCMAGN 294
Cdd:cd04967      9 DDTIFPEDS------DEKKVALNCRARANPVPSYRWLMNGTEIDLESDYR--YSLVDGTLVisNPSkakDAGHYQCLATN 80


                   ....*
gi 2217283229  295 KSGDV 299
Cdd:cd04967     81 TVGSV 85

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 43.60 E-value: 3.49e-05

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  139 IGCRvPESNPKAEVRYKIRGKWLEHSTEnYLILPSGNLQILNVSLEDKGSYKCAAYN 195
Cdd:cd04969     22 IECK-PKASPKPTISWSKGTELLTNSSR-ICILPDGSLKIKNVTKSDEGKYTCFAVN 76

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 43.35 E-value: 3.96e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIH---PSARHLTAGNGLKISGVTVEDVGMYQCVADN 384
Cdd:cd05867      7 QSHLYGPGETARLDCQVEGIPTPNITWSINGAPIEgtdPDPRRHVSSGALILTDVQPSDTAVYQCEARN 75

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 43.82 E-value: 3.96e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  420 DFVTLSCNASGLPVPVIRWYDSHGLITShpsqvlrsksrksqlsrpEGLNLEPVYFVLSQAGASSLHIQAVTQEHAGKYI 499
Cdd:cd05869     18 EQITLTCEASGDPIPSITWRTSTRNISS------------------EEKTLDGHIVVRSHARVSSLTLKYIQYTDAGEYL 79


                   ....*...
gi 2217283229  500 CEAANEHG 507
Cdd:cd05869     80 CTASNTIG 87

First immunoglobulin-like domains A168 within the A-band segment of human cardiac titin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domain A168 within the A-band segment of human cardiac titin. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structures of the titin-A168169 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409563 Cd Length: 93 Bit Score: 43.61 E-value: 3.97e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  318 LQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG-----LKISGVTVE-DVGMYQCVADNGIG 387
Cdd:cd20971      8 LRNLNVRYQSNATLVCKVTGHPKPIVKWYRQGKEIIADGLKYRIQEFkggyhQLIIASVTDdDATVYQVRATNQGG 83

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 43.30 E-value: 3.98e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  237 SPVTLECVVSGVPAPQVYWLK-DGqdiAPGSNWRRLYSH--LATDSVDPADSGNYSCMAGNKSGDVKY 301
Cdd:cd04968     17 QTVTLECFALGNPVPQIKWRKvDG---SPSSQWEITTSEpvLEIPNVQFEDEGTYECEAENSRGKDTV 81

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 42.77 E-value: 4.68e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  320 DQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLtagnglkISGVTVEDVGMYQCVADNG 385
Cdd:pfam13895    8 PTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSPNFF-------TLSVSAEDSGTYTCVARNG 66

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 43.16 E-value: 5.17e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217283229  337 GNPAPNCTWFHNAQPI---HPSARHLTAGNgLKISGVTVEDVGMYQCVADNGIGFMHS-TGRLEI 397
Cdd:cd05724     24 GHPEPTVSWRKDGQPLnldNERVRIVDDGN-LLIAEARKSDEGTYKCVATNMVGERESrAARLSV 87

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 43.39 E-value: 5.59e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  329 VHFTCDVHGNPAPNCTWFHNAQPIHPSARH---LTAGNGLKISGVTVEDVGMYQCVADNGIGFMHS 391
Cdd:cd05848     22 VILNCEARGNPVPTYRWLRNGTEIDTESDYrysLIDGNLIISNPSEVKDSGRYQCLATNSIGSILS 87

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 42.99 E-value: 6.14e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  313 SISKGLQDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARH-----LTAGNGLKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05763      1 SFTKTPHDITIRAGSTARLECAATGHPTPQIAWQKDGGTDFPAARErrmhvMPEDDVFFIVDVKIEDTGVYSCTAQNSAG 80

                           90
                   ....*....|
gi 2217283229  388 FMHSTGRLEI 397
Cdd:cd05763     81 SISANATLTV 90

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 42.88 E-value: 6.40e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  316 KGLQDQIVSLGATVHFTCD-VHGNPAPNCTWFHNAQPIHPS-ARHLTAGNG-----LKISGVTVEDVGMYQCVADNGIGF 388
Cdd:cd05750      4 KEMKSQTVQEGSKLVLKCEaTSENPSPRYRWFKDGKELNRKrPKNIKIRNKkknseLQINKAKLEDSGEYTCVVENILGK 83


                   ....*....
gi 2217283229  389 MHSTGRLEI 397
Cdd:cd05750     84 DTVTGNVTV 92

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 42.99 E-value: 6.97e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  130 TAEEKSAgfIGCRVpESNPKAEVRYKIRGKWLEHSTENYLILPSGNLQILN-VSLEDKGSYKCAAYNPV 197
Cdd:cd05850     18 SAEEKVT--LACRA-RASPPATYRWKMNGTELKMEPDSRYRLVAGNLVISNpVKAKDAGSYQCLASNRR 83

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 42.57 E-value: 8.41e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  231 LAVLSRSPVTLEC-VVSGVPAPQVYWLKDGQDIAPGS----NWRRLYSH-LATDSVDPADSGNYSCMAGNKSG 297
Cdd:pfam00047    6 VTVLEGDSATLTCsASTGSPGPDVTWSKEGGTLIESLkvkhDNGRTTQSsLLISNVTKEDAGTYTCVVNNPGG 78

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 42.40 E-value: 8.44e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217283229  321 QIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIhPSARHLTA--GNGLKISGVTVEDVGMYQCVADNGIGFMHST 392
Cdd:cd05731      5 TMVLRGGVLLLECIAEGLPTPDIRWIKLGGEL-PKGRTKFEnfNKTLKIENVSEADSGEYQCTASNTMGSARHT 77

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 42.46 E-value: 9.31e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217283229  227 HSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSHLATD--SVDPADSGNYSCMAGNKSGD 298
Cdd:cd05764      6 HTHELRVLEGQRATLRCKARGDPEPAIHWISPEGKLISNSSRTLVYDNGTLDilITTVKDTGAFTCIASNPAGE 79

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 42.59 E-value: 9.60e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNW-----RRLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05891     11 VTIMEGKTLNLTCTVFGNPDPEVIWFKNDQDIELSEHYsvkleQGKYASLTIKGVTSEDSGKYSINVKNKYG 82

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 42.38 E-value: 1.04e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   32 TSEPLSAVQklggPVVLHCSAQPVTTRISWLHNGKTLDGNlEHVKIHQG--TLTILSLNSSLLGYYQCLANNSIGAIVSG 109
Cdd:cd05740      8 NSNPVEDKD----AVTLTCEPETQNTSYLWWFNGQSLPVT-PRLTLSNGnrTLTLLNVTREDAGAYQCEISNPVSANRSD 82


                   ....*.
gi 2217283229  110 PATVSV 115
Cdd:cd05740     83 PVTLDV 88

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 42.45 E-value: 1.08e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH------LATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05892      8 QNKKVLEGDPVRLECQISAIPPPQIFWKKNNEMLQYNTDRISLYQDncgricLLIQNANKKDAGWYTVSAVNEAG 82

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 42.23 E-value: 1.09e-04

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*....
gi 2217283229  147 NPKAEVRYkIRGKWLEHSTENYLILPSGNLQILNVSLEDKGSYKCAAYN 195
Cdd:cd20968     26 NPKPSVSW-IKGDDLIKENNRIAVLESGSLRIHNVQKEDAGQYRCVAKN 73

Immunoglobulin C1-set domain;

Pssm-ID: 462221 Cd Length: 85 Bit Score: 41.85 E-value: 1.09e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  236 RSPVTLECVVSGV-PAP-QVYWLKDGQDIAPG---------SNWR-RLYSHLATDSVDPADSGNYSCMAGNKS 296
Cdd:pfam07654   12 GKPNTLTCLVTGFyPPDiTVTWLKNGQEVTEGvkttppspnSDWTyQLSSYLTVTPSDWESGDEYTCRVEHEG 84

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 41.40 E-value: 1.19e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  239 VTLECVVSGVPAPQVYWLKDGQDIAPGSNWR-RLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05746      1 VQIPCSAQGDPEPTITWNKDGVQVTESGKFHiSPEGYLAIRDVGVADQGRYECVARNTIG 60

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 41.72 E-value: 1.62e-04

                            10        20        30        40        50
                    ....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229   141 CRVPeSNPKAEVR-YKIRGKWLEHStENYLILPSGN---LQILNVSLEDKGSYKCAAYN 195
Cdd:smart00410   16 CEAS-GSPPPEVTwYKQGGKLLAES-GRFSVSRSGStstLTISNVTPEDSGTYTCAATN 72

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 41.77 E-value: 1.87e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  325 LGATVHFTCDVHGNPAPNCTWFHNAQPIHPSarhlTAGNG------LKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05856     18 VGSSVRLKCVASGNPRPDITWLKDNKPLTPP----EIGENkkkkwtLSLKNLKPEDSGKYTCHVSNRAGEINATYKVDV 92

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 41.23 E-value: 2.06e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  328 TVHFTCDVHGNPApNCTWFHNAQPIHPSAR-HLTAGNG-LKISGVTVEDVGMYQCVADNGIGFMHS 391
Cdd:cd05740     17 AVTLTCEPETQNT-SYLWWFNGQSLPVTPRlTLSNGNRtLTLLNVTREDAGAYQCEISNPVSANRS 81

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 41.45 E-value: 2.10e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  220 VHILHPthSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYS---HLATDSVDPADSGNYSCMAGNKS 296
Cdd:cd05760      2 VVLKHP--ASAAEIQPSSRVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVSSkerTLTLRSAGPDDSGLYYCCAHNAF 79


                   ...
gi 2217283229  297 GDV 299
Cdd:cd05760     80 GSV 82

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 41.46 E-value: 2.15e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  325 LGATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLT---AGNGLKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05730     17 LGQSVTLACDADGFPEPTMTWTKDGEPIESGEEKYSfneDGSEMTILDVDKLDEAEYTCIAENKAG 82

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for FGFs. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409363 Cd Length: 102 Bit Score: 41.25 E-value: 2.72e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  321 QIVSLGATVHFTCDVHGNPAPNCTWFH----NAQPIHP------------SARHLTAGNGLKISGVTVEDVGMYQCVADN 384
Cdd:cd04974     11 QTVVLGSDVEFHCKVYSDAQPHIQWLKhvevNGSKYGPdglpyvtvlkvaGVNTTGEENTLTISNVTFDDAGEYICLAGN 90


                   ....*...
gi 2217283229  385 GIGF-MHS 391
Cdd:cd04974     91 SIGLsFHS 98

Fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule); The members here are composed of the fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six IG-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409454 Cd Length: 89 Bit Score: 41.12 E-value: 2.94e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPIH-----PSARhlTAGNGLKISGVTVEDVGMYQCVADNGIGFM 389
Cdd:cd05868      7 TNLVLSPGEDGTLICRANGNPKPSISWLTNGVPIEiaptdPSRK--VDGDTIIFSKVQERSSAVYQCNASNEYGYL 80

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 41.18 E-value: 3.15e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYDSHGLITshpsqvlrsksrksqLSRPEGLNLEpvyfvlSQAGASS 484
Cdd:cd20974      1 PVFTQPLQSVVVLEGSTATFEAHVSGKPVPEVSWFRDGQVIS---------------TSTLPGVQIS------FSDGRAK 59

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20974     60 LSIPAVTKANSGRYSLTATNGSGQATSTAELLV 92

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 40.85 E-value: 3.32e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  405 PVIITAPVSAKVADGDFVTLSCNASGLPVPVIRWYdshglITSHPsqvLRSKSRKSQLSRPEGLNlepvyfvlsqagasS 484
Cdd:cd20990      1 PHFLQAPGDLTVQEGKLCRMDCKVSGLPTPDLSWQ-----LDGKP---IRPDSAHKMLVRENGVH--------------S 58

                           90       100       110
                   ....*....|....*....|....*....|...
gi 2217283229  485 LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20990     59 LIIEPVTSRDAGIYTCIATNRAGQNSFNLELVV 91

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 40.89 E-value: 3.53e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  240 TLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLYSH---LATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd04978     18 ELICEAEGNPQPTITWRLNGVPIEPAPEDMRRTVDgrtLIFSNLQPNDTAVYQCNASNVHG 78

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 40.78 E-value: 3.75e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  240 TLECVVSGVPAPQVYWLKDGQ----DIAPGSNWRRLYSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd20949     18 TILCEVKGEPQPNVTWHFNGQpisaSVADMSKYRILADGLLINKVTQDDTGEYTCRAYQVNS 79

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 40.63 E-value: 4.01e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   35 PLSAVQklGGPVVLHC--SAQPVTTrISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSL-LGYYQCLANNSIGAIVSGPA 111
Cdd:cd20958      9 NLTAVA--GQTLRLHCpvAGYPISS-ITWEKDGRRLPLNHRQRVFPNGTLVIENVQRSSdEGEYTCTARNQQGQSASRSV 85


                   ....
gi 2217283229  112 TVSV 115
Cdd:cd20958     86 FVKV 89

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 40.59 E-value: 4.04e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229   35 PLSA-----VQKL--GGPVVLHCSAQ--PVTTrISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSLLGYYQCLANN 101
Cdd:cd20957      1 PLSAtidppVQTVdfGRTAVFNCSVTgnPIHT-VLWMKDGKPLGHSSRVQILSEDVLVIPSVKREDKGMYQCFVRN 75

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 40.64 E-value: 4.14e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   41 KLGGPVVLHCSAQPVTTR--ISWLHNGKTLDGNLEHVK----IHQGTLTILSLNSSLLGYYQCLANNSigaivSGPATVS 114
Cdd:pfam00047    9 LEGDSATLTCSASTGSPGpdVTWSKEGGTLIESLKVKHdngrTTQSSLLISNVTKEDAGTYTCVVNNP-----GGSATLS 83


                   ...
gi 2217283229  115 VAV 117
Cdd:pfam00047   84 TSL 86

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 40.52 E-value: 4.22e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  416 VADGDFVTLSCNASGLPVPVIRWydshglitSHPSQVLRSKSRKSQLsrPEGlnlepvyfvlsqagasSLHIQAVTQEHA 495
Cdd:cd04969     14 AAKGGDVIIECKPKASPKPTISW--------SKGTELLTNSSRICIL--PDG----------------SLKIKNVTKSDE 67

                           90       100
                   ....*....|....*....|..
gi 2217283229  496 GKYICEAANEHGTTQAEASLMV 517
Cdd:cd04969     68 GKYTCFAVNFFGKANSTGSLSV 89

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 40.59 E-value: 4.41e-04

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  238 PVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRLY-SHLATDSVDPADSGNYSCMAGN 294
Cdd:cd20957     18 TAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSeDVLVIPSVKREDKGMYQCFVRN 75

Third immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The third Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409569 Cd Length: 93 Bit Score: 40.45 E-value: 4.45e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  319 QDQIVSLGATVHFTCDVHGNPAPNCTWFHNAQPI--HPSAR----HLTAGNGLKISGVTVEDVGMYQCVADNGIGF--MH 390
Cdd:cd20977      8 KDMMAKAGDVTMIYCMYGSNPTAHPNYFKNGKDVngNPEDRitrhNRTSGKRLLFKTTLPEDEGVYTCEVDNGVGKpqKH 87


                   ..
gi 2217283229  391 ST 392
Cdd:cd20977     88 SL 89

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 40.28 E-value: 4.84e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217283229   43 GGPVVLHCSAQPVTT-RISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAiVSGPATVSV 115
Cdd:cd05876     10 GQSLVLECIAEGLPTpTVKWLRPSGPLPPDRVKYQNHNKTLQLLNVGESDDGEYVCLAENSLGS-ARHAYYVTV 82

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 40.23 E-value: 5.07e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  407 IITAPVsakvadGDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQvlRSKSRKSQLSRPeglNLEPvyfvlsqagasslh 486
Cdd:cd05856     13 VIARPV------GSSVRLKCVASGNPRPDITWLKDNKPLTPPEIG--ENKKKKWTLSLK---NLKP-------------- 67

                           90       100
                   ....*....|....*....|....*
gi 2217283229  487 iqavtqEHAGKYICEAANEHGTTQA 511
Cdd:cd05856     68 ------EDSGKYTCHVSNRAGEINA 86

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 40.24 E-value: 5.17e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG-LKISGVT-VEDVGMYQCVADN 384
Cdd:cd20958     15 GQTLRLHCPVAGYPISSITWEKDGRRLPLNHRQRVFPNGtLVIENVQrSSDEGEYTCTARN 75

Fifth domain (immunoglobulin-like) of Trk receptors TrkA, TrkB, and TrkC; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth domain of Trk receptors TrkA, TrkB, and TrkC, an immunoglobulin (Ig)-like domain which binds to neurotrophin. The Trk family of receptors are tyrosine kinase receptors. They are activated by dimerization, leading to autophosphorylation of intracellular tyrosine residues, and triggering the signal transduction pathway. TrkA, TrkB, and TrkC share significant sequence homology and domain organization. The first three domains are leucine-rich domains while the fourth and fifth domains are Ig-like domains playing a part in ligand binding. TrkA, TrkB, and TrkC mediate the trophic effects of the neurotrophin Nerve Growth Factor (NGF) family. TrkA is recognized by NGF. TrkB is recognized by brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-4. TrkC is recognized by NT-3. NT-3 is promiscuous as in some cell systems it activates TrkA and TrkB receptors. TrkA is a receptor found in all major NGF targets, including the sympathetic, trigeminal, and dorsal root ganglia, cholinergic neurons of the basal forebrain, and the striatum. TrKB transcripts are found throughout multiple structures of the central and peripheral nervous systems. The TrkC gene is expressed throughout the mammalian nervous system. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409360 Cd Length: 96 Bit Score: 40.46 E-value: 5.24e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217283229  335 VHGNPAPNCTWFHNAQPI-----HPSARHLTAGNGLKISGV------TVEDVGMYQCVADNGIG 387
Cdd:cd04971     22 VRGNPKPTLTWYHNGAVLnesdyIRTEIHYEAATPTEYHGClkfdnpTHVNNGNYTLVASNEYG 85

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 40.32 E-value: 5.71e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQKLGGPVVLHCSAQ--PvTTRISWLHNGKTLDGNlEHVKIHQ----GTLTILSLNSSLLGYYQCLANNS 102
Cdd:pfam07679    1 PKFTQKPKDVEVQEGESARFTCTVTgtP-DPEVSWFKDGQPLRSS-DRFKVTYeggtYTLTISNVQPDDSGKYTCVATNS 78

                           90
                   ....*....|...
gi 2217283229  103 IGAiVSGPATVSV 115
Cdd:pfam07679   79 AGE-AEASAELTV 90

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 40.30 E-value: 5.83e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAV---QKLGGPVVLHCSAQ--PVTTrISWLHNGKTLD-GNLEHVKIHQGTLTILS-LNSSLLGYYQCLANN 101
Cdd:cd04967      2 PVFEEQPDDTIfpeDSDEKKVALNCRARanPVPS-YRWLMNGTEIDlESDYRYSLVDGTLVISNpSKAKDAGHYQCLATN 80

                           90
                   ....*....|....*
gi 2217283229  102 SIGAIVSGPATVSVA 116
Cdd:cd04967     81 TVGSVLSREATLQFG 95

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 40.18 E-value: 6.68e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  130 TAEEKSAGFIGCRVpESNPKAEVRYKIRGKWLEHSTENYLILPSGN-LQILNVSLEDKGSYKCAAYN----PVTHQLKVE 204
Cdd:cd20970     13 TAREGENATFMCRA-EGSPEPEISWTRNGNLIIEFNTRYIVRENGTtLTIRNIRRSDMGIYLCIASNgvpgSVEKRITLQ 91

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 39.89 E-value: 6.75e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPS-ARHLTAGNGLKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05876     10 GQSLVLECIAEGLPTPTVKWLRPSGPLPPDrVKYQNHNKTLQLLNVGESDDGEYVCLAENSLG 72

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 39.30 E-value: 7.64e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  407 IITAPVSAkVADGDFVTLSCNASGLPVPVIRWYDSHGLITSHPsqvlrsksrksqlsrpeglnlepvyfvlsqagasSLH 486
Cdd:pfam13895    3 VLTPSPTV-VTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSP----------------------------------NFF 47

                           90       100
                   ....*....|....*....|....
gi 2217283229  487 IQAVTQEHAGKYICEAANEHGTTQ 510
Cdd:pfam13895   48 TLSVSAEDSGTYTCVARNGRGGKV 71

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 39.50 E-value: 8.43e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  237 SPVTLECVVSGVPAPQVYWLKDGQDIAPGSnwRRL------YSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05748      8 ESLRLDIPIKGRPTPTVTWSKDGQPLKETG--RVQiettasSTSLVIKNAKRSDSGKYTLTLKNSAG 72

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 39.93 E-value: 8.49e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  239 VTLECVVSGVPAPQVYWLKDGQDIAPGSNWRrlYS-----HLATDSVDPADSGNYSCMAGNKSGDV 299
Cdd:cd05848     22 VILNCEARGNPVPTYRWLRNGTEIDTESDYR--YSlidgnLIISNPSEVKDSGRYQCLATNSIGSI 85

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 39.61 E-value: 8.67e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  229 QALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIAPGSNWRRL----YSHLATDSVDPADSGNYSCMAGNKSG 297
Cdd:cd05738      7 QLKVVEKARTATMLCAASGNPDPEISWFKDFLPVDTATSNGRIkqlrSGALQIENSEESDQGKYECVATNSAG 79

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 39.40 E-value: 8.83e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  237 SPVTLECVVSGVPAPQVYWLKDGQDIaPGSNWR-RLYSH--LATDSVDPADSGNYSCMAGNKSGDV 299
Cdd:cd20952     15 GTVVLNCQATGEPVPTISWLKDGVPL-LGKDERiTTLENgsLQIKGAEKSDTGEYTCVALNLSGEA 79

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 39.40 E-value: 9.09e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  419 GDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVlrsksrksqlsrpeglnlepvyfVLSQAGASSLHIQAVTQEHAGKY 498
Cdd:cd05743      1 GETVEFTCVATGVPTPIINWRLNWGHVPDSARVS-----------------------ITSEGGYGTLTIRDVKESDQGAY 57

                           90
                   ....*....|
gi 2217283229  499 ICEAANEHGT 508
Cdd:cd05743     58 TCEAINTRGM 67

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 39.51 E-value: 1.04e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217283229  127 HVITAEEKSAG---FIGCrVPESNPKAEVRYKIRGKWLehSTENYLILPSGNLQILNVSLEDKGSYKCAAYN 195
Cdd:cd05728      4 KVISDTEADIGsslRWEC-KASGNPRPAYRWLKNGQPL--ASENRIEVEAGDLRITKLSLSDSGMYQCVAEN 72

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409365 Cd Length: 90 Bit Score: 39.12 E-value: 1.26e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  232 AVLSRSPVTLECVVSGVPAPQVYWLKDGqdIAPGSNWRRLYSH-LATDSVDPADSGNYSCMAGNKSGDVK 300
Cdd:cd04976     14 ATAGKRSVRLPMKVKAYPPPEVVWYKDG--LPLTEKARYLTRHsLIIKEVTEEDTGNYTILLSNKQSNVF 81

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-2 (KDR/Flk-1) is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGF-A also interacts with VEGFR-1, which it binds more strongly than VEGFR-2. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409450 Cd Length: 89 Bit Score: 39.14 E-value: 1.28e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  313 SISKGLQDQI-VSLGATVHFTCDVHGNPAPNCTWFHNAQPIHpsARH-LTAGNGLKISGVTVEDVGMYQCVADNGI 386
Cdd:cd05864      3 ALGSGMESLVeAKVGERVRIPVKYLGYPPPEIKWYKNGIPIE--SNHtIKAGHVLTIMEVTEKDAGNYTVVLTNPI 76

Purple acid Phosphatase, N-terminal domain; This domain is found at the N-terminus of Purple acid phosphatase proteins.

Pssm-ID: 465220 [Multi-domain] Cd Length: 93 Bit Score: 39.32 E-value: 1.32e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  724 PDRPTIS-TASETSVYVTWIPRANGGSPItafkVEY-KRMRTSNWLVAAE--------DIPPSKLSVEVRSLEPGSTYKF 793
Cdd:pfam16656    1 PEQVHLSlTGDSTSMTVSWVTPSAVTSPV----VQYgTSSSALTSTATATsstyttgdGGTGYIHRATLTGLEPGTTYYY 76


                   ..
gi 2217283229  794 RV 795
Cdd:pfam16656   77 RV 78

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 39.03 E-value: 1.34e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229   43 GGPVVLHCSA----QPVttrISWLHNGKTL-DGNLEHVKIHQGT-LTILSLNSSLLGYYQCLANNSIGAIVSGPATVSV 115
Cdd:cd20970     17 GENATFMCRAegspEPE---ISWTRNGNLIiEFNTRYIVRENGTtLTIRNIRRSDMGIYLCIASNGVPGSVEKRITLQV 92

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 39.14 E-value: 1.35e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  308 VLEHASISKGLQDQivslgATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGN---GLKISGVTVEDVGMYQCVADN 384
Cdd:cd05760      3 VLKHPASAAEIQPS-----SRVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVSSkerTLTLRSAGPDDSGLYYCCAHN 77


                   ...
gi 2217283229  385 GIG 387
Cdd:cd05760     78 AFG 80

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 38.38 E-value: 1.62e-03

                           10        20        30
                   ....*....|....*....|....*....|...
gi 2217283229  168 YLILPSGNLQILNVSLEDKGSYKCAAYNPVTHQ 200
Cdd:cd05745     34 HLVLSSGTLRISRVALHDQGQYECQAVNIVGSQ 66

Immunoglobulin C-Type;

Pssm-ID: 214651 Cd Length: 75 Bit Score: 38.45 E-value: 1.63e-03

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229   238 PVTLECVVSGV-PAP-QVYWLKDGQDIAPG---------SNWR-RLYSHLATDSVDPADSGNYSCM 291
Cdd:smart00407    1 KATLVCLVSGFyPPDiTVTWLRNGQEVTEGvsttdplknSDGTyFLSSYLTVPASTWESGDVYTCQ 66

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 38.91 E-value: 1.74e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  312 ASISKGLQDQI-VSLGATVHFTCDVHGNPAPNCTWFHNAqpIHP-----SARH-LTAGNGLKISGVTVEDVGMYQCVADN 384
Cdd:cd20969      2 AAIRDRKAQQVfVDEGHTVQFVCRADGDPPPAILWLSPR--KHLvsaksNGRLtVFPDGTLEVRYAQVQDNGTYLCIAAN 79


                   ...
gi 2217283229  385 GIG 387
Cdd:cd20969     80 AGG 82

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 38.81 E-value: 1.90e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  318 LQDQIVslgatvhFTCDVHGNPAPNCTWFHNAQPIHPSAR----HLTAGNGLKISGVTVEDV-----GMYQCVADNGIG 387
Cdd:cd05869     16 LEEQIT-------LTCEASGDPIPSITWRTSTRNISSEEKtldgHIVVRSHARVSSLTLKYIqytdaGEYLCTASNTIG 87

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 39.01 E-value: 1.93e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  419 GDFVTLSCNASGLPVPVIRWYDSHGLITSHPSQVLRSKSRKSQLSRpeglnlepvyfvlsqagaSSLHIQAVTQEHAGKY 498
Cdd:cd05734     16 GKAVVLNCSADGYPPPTIVWKHSKGSGVPQFQHIVPLNGRIQLLSN------------------GSLLIKHVLEEDSGYY 77

                           90
                   ....*....|
gi 2217283229  499 ICEAANEHGT 508
Cdd:cd05734     78 LCKVSNDVGA 87

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 38.54 E-value: 2.04e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  141 CRVPESNPKAEVRYKIRGKWLEHSTENYLILPSGNLQILNVSLEDKGSYKCAAYNPVTH 199
Cdd:cd05724     19 CSPPRGHPEPTVSWRKDGQPLNLDNERVRIVDDGNLLIAEARKSDEGTYKCVATNMVGE 77

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 38.35 E-value: 2.32e-03

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*...
gi 2217283229   59 ISWLHNGKTLDGNlEHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAI 106
Cdd:cd05728     31 YRWLKNGQPLASE-NRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTI 77

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 38.28 E-value: 2.56e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  141 CRVpESNPKAEVRYKIRGKWLEHSTENYLILPSgNLQILNVSLEDKGSYKCAAYNPV 197
Cdd:cd20957     23 CSV-TGNPIHTVLWMKDGKPLGHSSRVQILSED-VLVIPSVKREDKGMYQCFVRNDG 77

Third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein) and similar proteins. WFIKKN is a secreted protein that consists of multiple types of protease inhibitory modules, including two tandem Kunitz-type protease inhibitor-domains. The Ig superfamily is a heterogenous group of proteins built on a common fold comprised of a sandwich of two beta sheets. Members of the Ig superfamily are components of immunoglobulin, neuroglia, cell surface glycoproteins, such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409422 [Multi-domain] Cd Length: 95 Bit Score: 38.30 E-value: 2.58e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  321 QIVSLGATVHFTCDVHGNPAPNCTWFHNA--------QPIHPSARHLTAGNG-LKISGVTVEDVGMYQCVADNGIGFM 389
Cdd:cd05765     10 QTVKVGETASFHCDVTGRPQPEITWEKQVpgkenlimRPNHVRGNVVVTNIGqLVIYNAQPQDAGLYTCTARNSGGLL 87

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 38.37 E-value: 2.67e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQKLGGP---VVLHCSAQ---PVTTRisWLHNGKTLD-GNLEHVKIHQGTLTILS-LNSSLLGYYQCLAN 100
Cdd:cd05850      3 PVFEEQPSSTLFPEGSAeekVTLACRARaspPATYR--WKMNGTELKmEPDSRYRLVAGNLVISNpVKAKDAGSYQCLAS 80

                           90
                   ....*....|...
gi 2217283229  101 NSIGAIVSGPATV 113
Cdd:cd05850     81 NRRGTVVSREASL 93

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 37.94 E-value: 2.90e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217283229  323 VSLGATVHFTCDVH-GNPAPNCTWFHNAQPIHPSARHL-----TAGNGLKISGVTVEDVGMYQCVADNGIG 387
Cdd:pfam00047    8 VLEGDSATLTCSAStGSPGPDVTWSKEGGTLIESLKVKhdngrTTQSSLLISNVTKEDAGTYTCVVNNPGG 78

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 38.28 E-value: 2.94e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  419 GDFVTLSCNASGLPVPVIRWYdshglitsHPSQVLRSKSRKSQLSRPeglnlepvyfvlsqagasSLHIQAVTQEHAGKY 498
Cdd:cd20957     16 GRTAVFNCSVTGNPIHTVLWM--------KDGKPLGHSSRVQILSED------------------VLVIPSVKREDKGMY 69

                           90
                   ....*....|....*..
gi 2217283229  499 ICEAANEHGTTQAEASL 515
Cdd:cd20957     70 QCFVRNDGDSAQATAEL 86

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 38.06 E-value: 3.28e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHLTAGNG-LKISGVTVEDVGMYQCVADNGIGFMHSTGRLEI 397
Cdd:cd05852     17 GGRVIIECKPKAAPKPKFSWSKGTELLVNNSRISIWDDGsLEILNITKLDEGSYTCFAENNRGKANSTGVLSV 89

First immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for all FGFs.

Pssm-ID: 409362 Cd Length: 94 Bit Score: 37.95 E-value: 3.45e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  215 PSSDDVHILHPThsqalavlsrSPVTLECVVSGVPApQVYWLKDGQDIAPGSNWRRLYSHLATDSVDPADSGNYSCMAGN 294
Cdd:cd04973     13 ISEVESYSAHPG----------DLLQLRCRLRDDVQ-SINWTKDGVQLGENNRTRITGEEVQIKDAVPRDSGLYACVTSS 81

                           90
                   ....*....|....*
gi 2217283229  295 KSGdvKYVTY-MVNV 308
Cdd:cd04973     82 PSG--SDTTYfSVNV 94

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 38.06 E-value: 3.51e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  139 IGCRvPESNPKAEVRYKIRGKWLEHSTEnYLILPSGNLQILNVSLEDKGSYKCAAYN 195
Cdd:cd05852     22 IECK-PKAAPKPKFSWSKGTELLVNNSR-ISIWDDGSLEILNITKLDEGSYTCFAEN 76

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 37.47 E-value: 3.52e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229  326 GATVHFTCDVHGNPAPNCTWFHNAQPIHPSARHL-TAGNG---LKISGVTVEDVGMYQCVADNGIG 387
Cdd:cd05743      1 GETVEFTCVATGVPTPIINWRLNWGHVPDSARVSiTSEGGygtLTIRDVKESDQGAYTCEAINTRG 66

First immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK). Tyro3 together with Axl and Mer form the Axl/Tyro3 family of receptor tyrosine kinases (RTKs). This family includes Axl (also known as Ark, Ufo, and Tyro7), Tyro3 (also known as Sky, Rse, Brt, Dtk, and Tif), and Mer (also known as Nyk, c-Eyk, and Tyro12). Axl/Tyro3 family receptors have an extracellular portion with two Ig-like domains followed by two fibronectin-types III (FNIII) domains, a membrane-spanning single helix, and a cytoplasmic tyrosine kinase domain. Axl, Tyro3 and Mer are widely expressed in adult tissues, though they show higher expression in the brain, in the lymphatic and vascular systems, and in the testis. Axl, Tyro3, and Mer bind the vitamin K dependent protein Gas6 with high affinity, and in doing so activate their tyrosine kinase activity. Axl/Gas6 signaling may play a part in cell adhesion processes, prevention of apoptosis, and cell proliferation.

Pssm-ID: 409553 Cd Length: 87 Bit Score: 37.81 E-value: 3.58e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGqdiAPGSNWRRLY---------SHLATDSVDPADSGNYSC 290
Cdd:cd20961      3 LTVSQGQPVKLNCSVEGMEEPDIQWVKDG---AVVQNLDQLYipvseqhwiGFLSLKSVERSDAGRYWC 68

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 37.86 E-value: 4.06e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  417 ADGDFVTLSCNASGLPVPV-IRWY-DSHGLITSHPSQVLRSKSRksqlsrpeglnlepvyfvlsqagASSLHIQAVTQEH 494
Cdd:cd20959     15 QVGMRAQLHCGVPGGDLPLnIRWTlDGQPISDDLGITVSRLGRR-----------------------SSILSIDSLEASH 71

                           90       100
                   ....*....|....*....|...
gi 2217283229  495 AGKYICEAANEHGTTQAEASLMV 517
Cdd:cd20959     72 AGNYTCHARNSAGSASYTAPLTV 94

Immunoglobulin (Ig)-like domain of semaphorin 4D (Sema4D) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of semaphorin 4D (Sema4D) and similar proteins. Sema4D is a Class IV semaphorin. Semaphorins are classified based on structural features additional to the Sema domain. Sema4D has extracellular Sema and Ig domains, a transmembrane domain, and a short cytoplasmic domain. Sema4D plays a part in the development of GABAergic synapses. Sema4D in addition is an immune semaphorin. It is abundant on resting T cells; its expression is weak on resting B cells and antigen presenting cells (APCs), but is upregulated by various stimuli. The receptor used by Sema4D in the immune system is CD72. Sem4D enhances the activation of B cells and DCs through binding CD72, perhaps by reducing CD72s inhibitory signals. The receptor used by Sema4D in the non-lymphatic tissues is plexin-B1. Sem4D is anchored to the cell surface but its extracellular domain can be released from the cell surface by a metalloprotease-dependent process. Sem4D may mediate its effects in its membrane-bound form and/or its cleaved form.

Pssm-ID: 409457 Cd Length: 87 Bit Score: 37.49 E-value: 4.50e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217283229   34 EPLSAVQKLGGPVVLHCSAQPVTTRISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSLLGYYQCLA 99
Cdd:cd05873      2 DPRQRTFKLGGNAELKCSPKSNLARVVWKFQGKVLKAESPKYGLYGDGLLIFNASEADAGRYQCLS 67

Immunoglobulin (Ig)-like domain at the C-terminus of semaphorins; The members here are composed of the immunoglobulin (Ig)-like domain in semaphorins. Semaphorins are transmembrane protein that have important roles in a variety of tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. Later they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. Semaphorins function through binding to their receptors and transmembrane semaphorins also serves as receptors themselves. Although molecular mechanism of semaphorins is poorly understood, the Ig-like domains may be involved in ligand binding or dimerization.

Pssm-ID: 409368 Cd Length: 88 Bit Score: 37.44 E-value: 4.57e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229   41 KLGGPVVLHCSAQPVTTRISWLHNGKTLDGNL--EHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAIVSGPATVSVA 116
Cdd:cd04979      9 KEGDTVILSCSVKSNNAPVTWIHNGKKVPRYRspRLVLKTERGLLIRSAQEADAGVYECHSGERVLGSTLRSVTLHVL 86

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 37.43 E-value: 4.58e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   30 YFTSEPLSAVQKLGGPVVLHCSAQPVTT-RISWLHNGKTLD--GNLEHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAI 106
Cdd:cd04978      1 YWIIEPPSLVLSPGETGELICEAEGNPQpTITWRLNGVPIEpaPEDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHGYL 80

                           90
                   ....*....|..
gi 2217283229  107 VsgpATVSVAVL 118
Cdd:cd04978     81 L---ANAFLHVL 89

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for FGFs. FGFR2 is required for male sex determination. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409444 Cd Length: 105 Bit Score: 38.02 E-value: 4.63e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  411 PVSAKVADGDFVTLSCNASGLPVPVIRWydshglitshpsqvLRSKSRKSQLSRPEGLnlePVYFVLSQAGASS------ 484
Cdd:cd05858      8 PANTSVVVGTDAEFVCKVYSDAQPHIQW--------------LKHVEKNGSKYGPDGL---PYVEVLKTAGVNTtdkeie 70

                           90       100       110
                   ....*....|....*....|....*....|....
gi 2217283229  485 -LHIQAVTQEHAGKYICEAANEHGTTQAEASLMV 517
Cdd:cd05858     71 vLYLRNVTFEDAGEYTCLAGNSIGISHHSAWLTV 104

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 37.54 E-value: 4.99e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217283229  319 QDQIVSLGATVHFTCDVHG-NPAPNCTWFHNAQPIHPSARHLtagNG-LKISGVTVEDVGMYQCVADN 384
Cdd:cd05754      9 RSQEVRPGADVSFICRAKSkSPAYTLVWTRVNGTLPSRAMDF---NGiLTIRNVQLSDAGTYVCTGSN 73

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 37.92 E-value: 5.10e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  227 HSQALAVLSRSPVTLECVVSGVPAPQVYWLKDGQDiapgsnwrrlyshLATDSVDP------------------------ 282
Cdd:cd07693      6 HPSDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQP-------------LETDKDDPrshrivlpsgslfflrvvhgrkgr 72

                           90
                   ....*....|....*
gi 2217283229  283 ADSGNYSCMAGNKSG 297
Cdd:cd07693     73 SDEGVYVCVAHNSLG 87

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 37.16 E-value: 5.73e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 2217283229  141 CRVpESNPKAEVRYKIRGKWL--EHSTENYLILPSGNLQILNVSLEDKGSYKCAAYN 195
Cdd:pfam13927   23 CEA-TGSPPPTITWYKNGEPIssGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 37.29 E-value: 5.85e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   29 PYFTSEPLSAVQKLGGPVVLHCSAQPVTT-RISWLHNGKTLDGNLE------HVKIH-QGTLTILSLNSSLLGYYQCLAN 100
Cdd:cd20954      2 PRWIVEPVDANVAAGQDVMLHCQADGFPTpTVTWKKATGSTPGEYKdllydpNVRILpNGTLVFGHVQKENEGHYLCEAK 81


                   ....*...
gi 2217283229  101 NSIGAIVS 108
Cdd:cd20954     82 NGIGSGLS 89

Immunoglobulin (Ig)-like domain of the class IV semaphorin Sema4B; The members here are composed of the immunoglobulin (Ig)-like domain of Sema4B and similar proteins. Sema4B is a Class IV semaphorin. Semaphorins are classified based on structural features additional to the Sema domain. Sema4B has extracellular Sema and Ig domains, a transmembrane domain, and a short cytoplasmic domain. Sema4B has been shown to preferentially regulate the development of the postsynaptic specialization at the glutamatergic synapses. This cytoplasmic domain includes a PDZ-binding motif upon which the synaptic localization of Sem4B is dependent. Sema4B is a ligand of CLCP1. CLCP1 was identified in an expression profiling analysis, which compared a highly metastic lung cancer subline with its low metastic parental line. Sema4B was shown to promote CLCP1 endocytosis and their interaction is a potential target for therapeutic intervention of metastasis.

Pssm-ID: 409456 Cd Length: 86 Bit Score: 37.03 E-value: 6.16e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217283229  323 VSLGATVHFTCDVHGNPApNCTWFHNAQPIHPSARHLTAG-NGLKISGVTVEDVGMYQCVADNGiGFMH 390
Cdd:cd05872      8 VVAGADVVLPCQLRSNLA-SPVWLFNGTPLNAQFSYLRLGtDGLLILVTSPEHSGTYRCYSEEE-GFQQ 74

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 37.18 E-value: 6.85e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  239 VTLECVVSGVPAPQVYWLKDGQDIAP-GSNWRRLYSH--LATDSVDPADSGNYSCMAGNKSGDVKYVTYM 305
Cdd:cd05867     17 ARLDCQVEGIPTPNITWSINGAPIEGtDPDPRRHVSSgaLILTDVQPSDTAVYQCEARNRHGNLLANAHV 86

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 37.22 E-value: 6.90e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229   32 TSEPLSAVQKLGGPVVLHCSA----QPvttRISWLHNGKTLDGNLEHVKIHQGTLTILSLNSSLLGYYQCLANNSIGAIV 107
Cdd:cd20968      3 TRPPTNVTIIEGLKAVLPCTTmgnpKP---SVSWIKGDDLIKENNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLGIAY 79


                   ....*...
gi 2217283229  108 SGPATVSV 115
Cdd:cd20968     80 SKPVTIEV 87

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 37.21 E-value: 8.04e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  220 VHILHPTHSqalavlSRSPVTLECVVSGVPAPQVYWLKDGQDI--APGSNWRRLYSHLA-TDSVDPADSGNYSCMAGNKS 296
Cdd:cd05850     10 SSTLFPEGS------AEEKVTLACRARASPPATYRWKMNGTELkmEPDSRYRLVAGNLViSNPVKAKDAGSYQCLASNRR 83


                   ...
gi 2217283229  297 GDV 299
Cdd:cd05850     84 GTV 86

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 36.78 E-value: 9.16e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  231 LAVLSRSPVTLECVVSGVPAPQVYWLKDGQDIaPGSNWRRLYSH--LATDSVDPA-DSGNYSCMAGNKSG 297
Cdd:cd20958     10 LTAVAGQTLRLHCPVAGYPISSITWEKDGRRL-PLNHRQRVFPNgtLVIENVQRSsDEGEYTCTARNQQG 78

Immunoglobulin (Ig) variable (V) domain of T-cell receptor (TCR) alpha chain and similar proteins; The members here are composed of the immunoglobulin (Ig) variable domain of the alpha chain of alpha/beta T-cell antigen receptors (TCRs). TCRs mediate antigen recognition by T lymphocytes, and are composed of alpha and beta, or gamma and delta polypeptide chains with variable (V) and constant (C) regions. This group represents the variable domain of the alpha chain of TCRs and also includes the variable domain of delta chains of TCRs. Alpha/beta TCRs recognize antigen as peptide fragments presented by major histocompatibility complex (MHC) molecules. The variable domain of TCRs is responsible for antigen recognition, and is located at the N-terminus of the receptor. Gamma/delta TCRs recognize intact protein antigens directly without antigen processing and recognize MHC independently of the bound peptide. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

Pssm-ID: 409372 [Multi-domain] Cd Length: 109 Bit Score: 37.25 E-value: 9.30e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  411 PVSAKVADGDFVTLSCNASGLPVPVIRWYdshgliTSHPS---QVLRSKSRKSQLSRPEGLNLEpvyFVLSQaGASSLHI 487
Cdd:cd04983      5 PQSLSVQEGENVTLNCNYSTSTFYYLFWY------RQYPGqgpQFLIYISSDSGNKKKGRFSAT---LDKSR-KSSSLHI 74

                           90       100
                   ....*....|....*....|.
gi 2217283229  488 QAVTQEHAGKYICEAANEHGT 508
Cdd:cd04983     75 SAAQLSDSAVYFCALSESGGT 95

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 37.31 E-value: 9.36e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217283229  411 PVSAKVADGDFVTLSCNASGL-PVPVIRWY---DSHGLI------TSHPSQVLRSKSRKSQlsrpeglnlepvyfVLSQA 480
Cdd:cd00099      5 PRSLSVQEGESVTLSCEVSSSfSSTYIYWYrqkPGQGPEfliylsSSKGKTKGGVPGRFSG--------------SRDGT 70

                           90       100
                   ....*....|....*....|
gi 2217283229  481 GASSLHIQAVTQEHAGKYIC 500
Cdd:cd00099     71 SSFSLTISNLQPEDSGTYYC 90