PI31 proteasome regulator N-terminal; PI31 is a regulatory subunit of the immuno-proteasome which is an inhibitor of the 20 S proteasome in vitro.PI31 is also an F-box protein Fbxo7.Skp1 binding partner which requires an N terminal FP domain in both proteins for the interaction to occur via the FP beta sheets. The structure of PI31 FP domain contains a novel alpha/beta-fold and two intermolecular contact surfaces. This is the N-terminal domain of the members.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 74229027   189 SADCSDANDALIVLIHLLMLESGYIPQGT-------------EAKALSMPEKWK-LSGVYKLQYMHPLcegSSAT--LTC 252
Cdd:pfam11566   2 SSDLKSPYDALALLVHACMTALGFRLVGLgedkkieespselQSLAPRLPPGWNaGSGSYAFRYAHKQ---SSMEylLKV 78

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 74229027   253 VPLGNLIVVNAtlkINNEIRSVKRLQLLPESFI-----------CKEKLGeNVANIYKDLQKLSRLFKDQLVYPLL 317
Cdd:pfam11566  79 DRLGNKLVING---LALGDDKVASFEINVKDYVsssalplredrSDEKLG-DLFISYPRLEDLISLFKSNIIQKLV 150

first ubiquitin-like (Ubl) domain located at the N-terminus of coronavirus SARS-CoV non-structural protein 3 (Nsp3) and related proteins; This ubiquitin-like (Ubl) domain (Ubl1) is found at the N-terminus of coronavirus Nsp3, a large multi-functional multi-domain protein which is an essential component of the replication/transcription complex (RTC). The functions of Ubl1 in CoVs are related to single-stranded RNA (ssRNA) binding and to interacting with the nucleocapsid (N) protein. SARS-CoV Ubl1 has been shown to bind ssRNA having AUA patterns, and since the 5'-UTR of the SARS-CoV genome has a number of AUA repeats, it may bind there. In mouse hepatitis virus (MHV), this Ubl1 domain binds the cognate N protein. Adjacent to Ubl1 is a Glu-rich acidic region (also referred to as hypervariable region, HVR); Ubl1 together with HVR has been called Nsp3a. Currently, the function of HVR in CoVs is unknown. This model corresponds to one of two Ubl domains in Nsp3; the other is located N-terminal to the papain-like protease (PLpro) and is not represented by this model.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 74229027   1 MRLRVRLLK--RTWPLEVPETEpTLGHLRshlrqsLLCTW--GYSSNtRFTITLNYKdPLTGDEETLASYGIVSGDLICL 76
Cdd:cd01796   1 MKLTVTTEDddRLFSLEVSPDM-TLEDLK------ALCEAetGIPAA-EQVLLHNGQ-PLTDDKKTLEALGLKDGDLLLL 71

                .
gi 74229027  77 I 77
Cdd:cd01796  72 R 72

F-box-like; This is an F-box-like family.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 74229027   335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLY 376
Cdd:pfam12937   4 LPDEILLQIFSYLDPKDLLRLALVCRRWRELASDDSLWRRLC 45

A Receptor for Ubiquitination Targets;

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|.
gi 74229027    335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFL 375
Cdd:smart00256   1 LPDEILEEILSKLDPKDLLRLRKVSRKWRSLIDSHDFWFKL 41

ubiquitin-like (Ubl) domain found in the eukaryotic Ddi1 family; The eukaryotic Ddi1 family, including yeast aspartyl protease DNA-damage inducible 1 (Ddi1) and Ddi1-like proteins from vertebrates and other eukaryotes, has been characterized by containing an N-terminal ubiquitin-like (Ubl) domain and a conserved retroviral aspartyl-protease-like domain (RVP) that is important in cell-cycle control. Yeast Ddi1 and many family members also contain a C-terminal ubiquitin-association (UBA) domain, however, Ddi1-like proteins from all vertebrates lack the UBA domain. Ddi1, also termed v-SNARE-master 1 (Vsm1), is an ubiquitin receptor involved in the cell cycle and late secretory pathway in Saccharomyces cerevisiae. It functions as an UBA-Ubl shuttle protein that is required for the proteasome to enable ubiquitin-dependent degradation of its ligands. For instance, Ddi1 plays an essential role in the final stages of proteasomal degradation of Ho endonuclease and of its cognate FBP, Ufo1. Moreover, Ddi1 and its associated protein Rad23p play a cooperative role as negative regulators in yeast PHO pathway. This family also includes mammalian regulatory solute carrier protein family 1 member 1 (RSC1A1), also termed transporter regulator RS1 (RS1), which mediates transcriptional and post-transcriptional regulation of Na(+)-D-glucose cotransporter SGLT1. Ddi1-like proteins play a significant role in cell cycle control, growth control, and trafficking in yeast and may play a crucial role in embryogenesis in higher eukaryotes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 74229027   1 MRLRVRLLK--RTWPLEVPETEpTLGHLRshlrqsLLCTW--GYSSNtRFTITLNYKdPLTGDEETLASYGIVSGDLICL 76
Cdd:cd01796   1 MKLTVTTEDddRLFSLEVSPDM-TLEDLK------ALCEAetGIPAA-EQVLLHNGQ-PLTDDKKTLEALGLKDGDLLLL 71

                .
gi 74229027  77 I 77
Cdd:cd01796  72 R 72

F-box-like; This is an F-box-like family.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 74229027   335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLY 376
Cdd:pfam12937   4 LPDEILLQIFSYLDPKDLLRLALVCRRWRELASDDSLWRRLC 45

F-box domain found in F-box only protein 9 (FBXO9) and similar proteins; FBXO9, also called FBX9, cross-immune reaction antigen 1, renal carcinoma antigen NY-REN-57, or VCIA1, is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of TTI1 and TELO2 in a CK2-dependent manner, thereby directly regulating mTOR signaling. FBXO9 acts as an E3 ubiquitin ligase that regulates the stability and activity of peroxisome proliferator-activated receptor gamma (PPARgamma) through ubiquitination. It is also required for adipocyte differentiation. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 74229027 334 VLPLELKLRIFRL----LDVRSVLSLSAVCRDLFTASNDPLLWRFLYLR 378
Cdd:cd22089   5 ALPSEILLYILRWvvsdLDLRSLEQLSLVCRKFYLLARDPSIWRLACER 53

F-box domain found in F-box/LRR-repeat protein 4 (FBXL4) and similar proteins; FBXL4, also called F-box and leucine-rich repeat protein 4, or F-box protein FBL4/FBL5, is part of an SCF (SKP1-cullin-F-box) protein ligase complex. It serves as a clock output molecule that regulates sleep through promotion of rhythmic degradation of the GABA(A) receptor. Biallelic pathogenic variants in FBXL4 are associated with an encephalopathic mtDNA maintenance defect syndrome that is a multi-system disease characterized by lactic acidemia, developmental delay, and hypotonia. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 74229027 334 VLPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLYLR 378
Cdd:cd22117   3 LLPYELIQLILSYLDLPSLCRLSQTCKLFRKHCYDPLLWKELNLQ 47

F-box domain found in Saccharomyces cerevisiae mitochondrial F-box protein MFB1 (ScMFB1) and similar proteins; ScMFB1 is a novel mitochondria-associated F-box protein that functions to increase mitochondrial connectivity in yeast. ScMFB1 acts as a key component of a Skp1-Cdc53/Cullin-F-box protein (SCF) ubiquitin ligase complex machinery that regulates mitochondrial dynamics throughout the yeast's entire life cycle. It interacts with Skp1p in an F-box-dependent manner. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 74229027 335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWR 373
Cdd:cd22146   4 LPLEILFEILIYLDIPDILNLSKTCRFLYVLLNDEILWR 42

F-box domain found in Arabidopsis thaliana SKP1-interacting partner 22 (AtSKIP22) and similar proteins; AtSKIP22, also called F-box protein SKIP22, is a component of SCF (SKP1/ASK-cullin-F-box protein) E3 ubiquitin ligase complexes, which may mediate the ubiquitination and subsequent proteasomal degradation of target proteins. It interacts with SKP1A/ASK1 and SPK1B/ASK2. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 74229027 332 LVVLPLELKLRIFRLLDVRSVLSLSAVCRDL-FTASNDPLLWRF 374
Cdd:cd22165   2 LMRLPTELKLKILELLPGVDLARMACVCSELrFLASNDDLWKQK 45

F-box domain found in F-box only protein 41 (FBXO41) and similar proteins; FBXO41, also called FBX41, is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. It acts as a novel central nervous system (CNS)-specific F-box protein that localizes to the centrosome and the cytoplasm of neurons and promotes neuronal migration. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30
                ....*....|....*....|....*....|....
gi 74229027 343 IFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLY 376
Cdd:cd22109  14 VFSYLDTKSLLRCAEVCREWRDVSRHPALWQRVC 47

F-box domain found in F-box/WD repeat-containing protein 5 (FBXW5) and similar proteins; FBXW5, also called F-box and WD-40 domain-containing protein 5, is the substrate-recognition component of both SCF (SKP1-CUL1-F-box protein) and DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complexes. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 74229027 335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLY 376
Cdd:cd22132   4 LPDSLLLHIFSYLSPKDLLAAGQVCKQWYRVSRDEFLWKELF 45

F-box domain found in Arabidopsis thaliana SKP1-interacting partner 31 (AtSKIP31) and similar proteins; AtSKIP31, also called F-box protein SKIP31, is a component of SCF(ASK-cullin-F-box) E3 ubiquitin ligase complexes, which may mediate the ubiquitination and subsequent proteasomal degradation of target proteins. It interacts with SKP1A/ASK1 and SPK1B/ASK2. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 74229027 335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLY 376
Cdd:cd22166   4 LPPELFRHILKFLSPEDLTSCATVCRFLRGAASDESLWRRLY 45

A Receptor for Ubiquitination Targets;

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|.
gi 74229027    335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFL 375
Cdd:smart00256   1 LPDEILEEILSKLDPKDLLRLRKVSRKWRSLIDSHDFWFKL 41

F-box domain found in F-box only protein 4 (FBXO4) and similar proteins; FBXO4, also called FBX4, is a specific substrate-recognition component of an SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex that catalyzes the ubiquitination and subsequent degradation of cyclin D1 and Trx1. It recognizes TERF1 and promotes its ubiquitination together with UBE2D1. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 74229027 335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWRFLYLRD 379
Cdd:cd22085   6 LPIDLQLYILSFLSPHDLCQLGLTSHYWHTLVRDPLLWRYFLLRD 50

ubiquitin-like (Ubl) domain found in the eukaryotic Ddi1 family; The eukaryotic Ddi1 family, including yeast aspartyl protease DNA-damage inducible 1 (Ddi1) and Ddi1-like proteins from vertebrates and other eukaryotes, has been characterized by containing an N-terminal ubiquitin-like (Ubl) domain and a conserved retroviral aspartyl-protease-like domain (RVP) that is important in cell-cycle control. Yeast Ddi1 and many family members also contain a C-terminal ubiquitin-association (UBA) domain, however, Ddi1-like proteins from all vertebrates lack the UBA domain. Ddi1, also termed v-SNARE-master 1 (Vsm1), is an ubiquitin receptor involved in the cell cycle and late secretory pathway in Saccharomyces cerevisiae. It functions as an UBA-Ubl shuttle protein that is required for the proteasome to enable ubiquitin-dependent degradation of its ligands. For instance, Ddi1 plays an essential role in the final stages of proteasomal degradation of Ho endonuclease and of its cognate FBP, Ufo1. Moreover, Ddi1 and its associated protein Rad23p play a cooperative role as negative regulators in yeast PHO pathway. This family also includes mammalian regulatory solute carrier protein family 1 member 1 (RSC1A1), also termed transporter regulator RS1 (RS1), which mediates transcriptional and post-transcriptional regulation of Na(+)-D-glucose cotransporter SGLT1. Ddi1-like proteins play a significant role in cell cycle control, growth control, and trafficking in yeast and may play a crucial role in embryogenesis in higher eukaryotes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 74229027   1 MRLRVRLLK--RTWPLEVPETEpTLGHLRshlrqsLLCTW--GYSSNtRFTITLNYKdPLTGDEETLASYGIVSGDLICL 76
Cdd:cd01796   1 MKLTVTTEDddRLFSLEVSPDM-TLEDLK------ALCEAetGIPAA-EQVLLHNGQ-PLTDDKKTLEALGLKDGDLLLL 71

                .
gi 74229027  77 I 77
Cdd:cd01796  72 R 72

F-box domain found in uncharacterized F-box protein group similar to F-box only protein 3 (FBXO3); This subfamily corresponds to a group of uncharacterized F-box proteins which show sequence similarity to F-box only protein 3 (FBXO3). FBXO3, also called FBX3, is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex, that mediates the ubiquitination of HIPK2 and probably that of EP300, leading to rapid degradation by the proteasome. It also promotes ubiquitylation and transcriptional activity of AIRE (autoimmune regulator). The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 74229027 335 LPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWR 373
Cdd:cd22139   4 LPDELWLHIFSFLSPKDLCQVALVCRRFNRLASDESLWK 42

F-box domain found in F-box only protein 24 (FBXO24) and similar proteins; FBXO24, also called FBX24, is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. It recognizes deacetylated nucleoside diphosphate kinase A (NDPK-A) to enhance its degradation. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 74229027 332 LVVLPLELKLRIFRLLDVRSVLSLSAVCRDLFTASNDPLLWR 373
Cdd:cd22098   2 LLDLPPEILDRIISFLPVKDIVSLGQTCRYFHEVCNSEAVWR 43