C-type lectin (CTL) or carbohydrate-recognition domain (CRD); Many of these domains function as calcium-dependent carbohydrate binding modules.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192   291 CPVPAVNFKGLCYKMCRGLVKFEDSCTWC---NGTMATISSGEENDFVSRVFGSNDETTrQIWIG--------------N 353
Cdd:smart00034   1 CPSGWISYGGKCYKFSTEKKTWEDAQAFCqslGGHLASIHSEAENDFVASLLKNSGSSD-YYWIGlsdpdsngswqwsdG 79

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|..
gi 392901192   354 TESSGYLNWSQGQptkPNDGLDYCISMDlsagSTRGKYKYLPCQSTvINSLC 405
Cdd:smart00034  80 SGPVSYSNWAPGE---PNNSSGDCVVLS----TSGGKWNDVSCTSK-LPFVC 123

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192  86 CYRVSDAESEWHGGTAICKALNpdAEMASFHSQAESIFVAN---KYSTIHAWTGLSQTEIPNTWTYTDGTPDWHWFPALA 162
Cdd:cd00037    2 CYKFSTEKLTWEEAQEYCRSLG--GHLASIHSEEENDFLASllkKSSSSDVWIGLNDLSSEGTWKWSDGSPLVDYTNWAP 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 392901192 163 AAPSDADSS-CVEMmdgllglifaLSLQKGQTNAYSCDESIQIICKY 208
Cdd:cd00037   80 GEPNPGGSEdCVVL----------SSSSDGKWNDVSCSSKLPFICEK 116

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192 302 CYKMCRGLVKFEDSCTWC---NGTMATISSGEENDFVSRVFGSNDetTRQIWIG--------------NTESSGYLNWSQ 364
Cdd:cd00037    2 CYKFSTEKLTWEEAQEYCrslGGHLASIHSEEENDFLASLLKKSS--SSDVWIGlndlssegtwkwsdGSPLVDYTNWAP 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|.
gi 392901192 365 GQPtkPNDGLDYCISMDlsaGSTRGKYKYLPCqSTVINSLC 405
Cdd:cd00037   80 GEP--NPGGSEDCVVLS---SSSDGKWNDVSC-SSKLPFIC 114

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192  86 CYRVSDAESEWHGGTAICKALNpdAEMASFHSQAESIFVAN---KYSTIHAWTGLSQTEIPNTWTYTDGTPDWHWFPALA 162
Cdd:cd00037    2 CYKFSTEKLTWEEAQEYCRSLG--GHLASIHSEEENDFLASllkKSSSSDVWIGLNDLSSEGTWKWSDGSPLVDYTNWAP 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 392901192 163 AAPSDADSS-CVEMmdgllglifaLSLQKGQTNAYSCDESIQIICKY 208
Cdd:cd00037   80 GEPNPGGSEdCVVL----------SSSSDGKWNDVSCSSKLPFICEK 116

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192 302 CYKMCRGLVKFEDSCTWC---NGTMATISSGEENDFVSRVFGSNDetTRQIWIG--------------NTESSGYLNWSQ 364
Cdd:cd00037    2 CYKFSTEKLTWEEAQEYCrslGGHLASIHSEEENDFLASLLKKSS--SSDVWIGlndlssegtwkwsdGSPLVDYTNWAP 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|.
gi 392901192 365 GQPtkPNDGLDYCISMDlsaGSTRGKYKYLPCqSTVINSLC 405
Cdd:cd00037   80 GEP--NPGGSEDCVVLS---SSSDGKWNDVSC-SSKLPFIC 114

C-type lectin-like domain (CTLD) of the type found in natural killer cell receptors (NKRs); CLECT_NK_receptors_like: C-type lectin-like domain (CTLD) of the type found in natural killer cell receptors (NKRs), including proteins similar to oxidized low density lipoprotein (OxLDL) receptor (LOX-1), CD94, CD69, NKG2-A and -D, osteoclast inhibitory lectin (OCIL), dendritic cell-associated C-type lectin-1 (dectin-1), human myeloid inhibitory C-type lectin-like receptor (MICL), mast cell-associated functional antigen (MAFA), killer cell lectin-like receptors: subfamily F, member 1 (KLRF1) and subfamily B, member 1 (KLRB1), and lys49 receptors. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. NKRs are variously associated with activation or inhibition of natural killer (NK) cells. Activating NKRs stimulate cytolysis by NK cells of virally infected or transformed cells; inhibitory NKRs block cytolysis upon recognition of markers of healthy self cells. Most Lys49 receptors are inhibitory; some are stimulatory. OCIL inhibits NK cell function via binding to the receptor NKRP1D. Murine OCIL in addition to inhibiting NK cell function inhibits osteoclast differentiation. MAFA clusters with the type I Fc epsilon receptor (FcepsilonRI) and inhibits the mast cells secretory response to FcepsilonRI stimulus. CD72 is a negative regulator of B cell receptor signaling. NKG2D is an activating receptor for stress-induced antigens; human NKG2D ligands include the stress induced MHC-I homologs, MICA, MICB, and ULBP family of glycoproteins Several NKRs have a carbohydrate-binding capacity which is not mediated through calcium ions (e.g. OCIL binds a range of high molecular weight sulfated glycosaminoglycans including dextran sulfate, fucoidan, and gamma-carrageenan sugars). Dectin-1 binds fungal beta-glucans and in involved in the innate immune responses to fungal pathogens. MAFA binds saccharides having terminal alpha-D mannose residues in a calcium-dependent manner. LOX-1 is the major receptor for OxLDL in endothelial cells and thought to play a role in the pathology of atherosclerosis. Some NKRs exist as homodimers (e.g.Lys49, NKG2D, CD69, LOX-1) and some as heterodimers (e.g. CD94/NKG2A). Dectin-1 can function as a monomer in vitro.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192  73 CEAGWHQFPDTgcCYRVSDAESEWHGGTAICKALNpdAEMASFHSQAESIFVANKYSTIHAWTGLSQTEIPNTWTYTDGT 152
Cdd:cd03593    1 CPKDWICYGNK--CYYFSMEKKTWNESKEACSSKN--SSLLKIDDEEELEFLQSQIGSSSYWIGLSREKSEKPWKWIDGS 76

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 392901192 153 PdwhWFPALAAAPSDADSSCVemmdgllglifalSLQKGQTNAYSCDESIQIICK 207
Cdd:cd03593   77 P---LNNLFNIRGSTKSGNCA-------------YLSSTGIYSEDCSTKKRWICE 115

C-type lectin-like domain (CTLD) of the type found in CEL-1 from Cucumaria echinata and Echinoidin from Anthocidaris crassispina; CLECT_CEL-1_like: C-type lectin-like domain (CTLD) of the type found in CEL-1 from Cucumaria echinata and Echinoidin from Anthocidaris crassispina. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CEL-1 CTLD binds three calcium ions and has a high specificity for N-acteylgalactosamine (GalNAc). CEL-1 exhibits strong cytotoxicity which is inhibited by GalNAc. This protein may play a role as a toxin defending against predation. Echinoidin is found in the coelomic fluid of the sea urchin and is specific for GalBeta1-3GalNAc. Echinoidin has a cell adhesive activity towards human cancer cells which is not mediated through the CTLD. Both CEL-1 and Echinoidin are multimeric proteins comprised of multiple dimers linked by disulfide bonds.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192  73 CEAGWHQFpdTGCCYRVSDAESEWHGGTAICKALNPD---AEMASFHSQAESIFVANKYSTIH-------AWTGLSQTEI 142
Cdd:cd03589    1 CPTFWTAF--GGYCYRFFGDRLTWEEAELRCRSFSIPgliAHLVSIHSQEENDFVYDLFESSRgpdtpygLWIGLHDRTS 78

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 392901192 143 PNTWTYTDGTP-DW-HWFPalaAAPSDADSS--CVEMMDGLLGLifalslqkGQTNAYSCDESIQIICK 207
Cdd:cd03589   79 EGPFEWTDGSPvDFtKWAG---GQPDNYGGNedCVQMWRRGDAG--------QSWNDMPCDAVFPYICK 136

C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins; CLECT_CSPGs: C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins (CSPGs) in human and chicken aggrecan, frog brevican, and zebra fish dermacan. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. In cartilage, aggrecan forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Xenopus brevican is expressed in the notochord and the brain during early embryogenesis. Zebra fish dermacan is expressed in dermal bones and may play a role in dermal bone development. CSPGs do contain LINK domain(s) which bind HA. These LINK domains are considered by one classification system to be a variety of CTLD, but are omitted from this hierarchical classification based on insignificant sequence similarity.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192  73 CEAGWHQFpdTGCCYRVSDAESEWHGGTAICKalNPDAEMASFHSQAESIFVANKYSTiHAWTGLSQTEIPNTWTYTDGT 152
Cdd:cd03588    1 CEEGWDKF--QGHCYRHFPDRETWEDAERRCR--EQQGHLSSIVTPEEQEFVNNNAQD-YQWIGLNDRTIEGDFRWSDGH 75

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 392901192 153 PDW--HWFPALAAAPSDADSSCVEMmdgllglifaLSLQKGQTNAYSCDESIQIICK 207
Cdd:cd03588   76 PLQfeNWRPNQPDNFFATGEDCVVM----------IWHEEGEWNDVPCNYHLPFTCK 122

C-type lectin-like domain (CTLD) of the type found in Human REG-1 (lithostathine), REG-4, and avian eggshell-specific proteins: ansocalcin, structhiocalcin-1(SCA-1), and -2(SCA-2); CLECT_REG-1_like: C-type lectin-like domain (CTLD) of the type found in Human REG-1 (lithostathine), REG-4, and avian eggshell-specific proteins: ansocalcin, structhiocalcin-1(SCA-1), and -2(SCA-2). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. REG-1 is a proliferating factor which participates in various kinds of tissue regeneration including pancreatic beta-cell regeneration, regeneration of intestinal mucosa, regeneration of motor neurons, and perhaps in tissue regeneration of damaged heart. REG-1 may play a role on the pathophysiology of Alzheimer's disease and in the development of gastric cancers. Its expression is correlated with reduced survival from early-stage colorectal cancer. REG-1 also binds and aggregates several bacterial strains from the intestinal flora and it has been suggested that it is involved in the control of the intestinal bacterial ecosystem. Rat lithostathine has calcium carbonate crystal inhibitor activity in vitro. REG-IV is unregulated in pancreatic, gastric, hepatocellular, and prostrate adenocarcinomas. REG-IV activates the EGF receptor/Akt/AP-1 signaling pathway in colorectal carcinoma. Ansocalcin, SCA-1 and -2 are found at high concentration in the calcified egg shell layer of goose and ostrich, respectively and tend to form aggregates. Ansocalcin nucleates calcite crystal aggregates in vitro.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 392901192 291 CPVPAVNFKGLCYKMCRGLVKFEDSCTWCN-----GTMATISSGEENDFVSRVFGSNDETTRQIWIG------------- 352
Cdd:cd03594    1 CPKGWLPYKGNCYGYFRQPLSWSDAELFCQkygpgAHLASIHSPAEAAAIASLISSYQKAYQPVWIGlhdpqqsrgwews 80

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 392901192 353 NTESSGYLNWSQGQPTKPNdglDYCISMDLSAGSTR 388
Cdd:cd03594   81 DGSKLDYRSWDRNPPYARG---GYCAELSRSTGFLK 113