Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 J1, J2 and related proteins; The E2J subfamily includes mammalian ubiquitin-conjugating enzymes E2 J1 (UBE2J1/HSPC153/HSPC205/NCUBE1) and J2 (UBE2J2/NCUBE1), yeast ubiquitin-conjugating enzyme E2 6 (UBC6/DOA2), and plant ubiquitin-conjugating enzyme E2 32-34 (UBC32-34). They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2J1 and UBE2J2 are non-canonical ubiquitin-conjugating enzyme (NCUBE), which function in the selective degradation of misfolded membrane proteins from the endoplasmic reticulum (ERAD). Saccharomyces cerevisiae UBC6 functions in degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system. It is a cognate E2 conjugating enzyme for the DOA10 ubiquitin ligase complex, which is part of the ERAD-C pathway responsible for the rapid degradation of membrane proteins with misfolded cytoplasmic domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   5 RGGYYHGKLIFPREFPFKPPSIYMITPNGRFKCNTRLCLSITDFHPDTWNPAWSVSTILTGLLSFMVEKGPT-LGSIETS 83
Cdd:cd23799   43 EGGIYHGKIVFPPDYPFKPPSIYMLTPNGRFETNTKICLSISSFHPESWNPAWSIRTILIGLLSFMPEDEEGaGGSIDTS 122

                         90
                 ....*....|..
gi 767902207  84 DFTKRQLAVQSL 95
Cdd:cd23799  123 DEERRRLAKESR 134

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 J1, J2 and related proteins; The E2J subfamily includes mammalian ubiquitin-conjugating enzymes E2 J1 (UBE2J1/HSPC153/HSPC205/NCUBE1) and J2 (UBE2J2/NCUBE1), yeast ubiquitin-conjugating enzyme E2 6 (UBC6/DOA2), and plant ubiquitin-conjugating enzyme E2 32-34 (UBC32-34). They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2J1 and UBE2J2 are non-canonical ubiquitin-conjugating enzyme (NCUBE), which function in the selective degradation of misfolded membrane proteins from the endoplasmic reticulum (ERAD). Saccharomyces cerevisiae UBC6 functions in degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system. It is a cognate E2 conjugating enzyme for the DOA10 ubiquitin ligase complex, which is part of the ERAD-C pathway responsible for the rapid degradation of membrane proteins with misfolded cytoplasmic domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   5 RGGYYHGKLIFPREFPFKPPSIYMITPNGRFKCNTRLCLSITDFHPDTWNPAWSVSTILTGLLSFMVEKGPT-LGSIETS 83
Cdd:cd23799   43 EGGIYHGKIVFPPDYPFKPPSIYMLTPNGRFETNTKICLSISSFHPESWNPAWSIRTILIGLLSFMPEDEEGaGGSIDTS 122

                         90
                 ....*....|..
gi 767902207  84 DFTKRQLAVQSL 95
Cdd:cd23799  123 DEERRRLAKESR 134

Ubiquitin-conjugating enzyme; Proteins destined for proteasome-mediated degradation may be ubiquitinated. Ubiquitination follows conjugation of ubiquitin to a conserved cysteine residue of UBC homologs. TSG101 is one of several UBC homologs that lacks this active site cysteine.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767902207    6 GGYYHGKLIFPREFPFKPPSIYMITPngRFKCNT----RLCLSItdFHPDTWNPAWSVSTILTGLLSFMVEKGPT 76
Cdd:pfam00179  43 GGVFKLSVEFPEDYPFKPPKVKFTTK--IYHPNVdssgEVCLDI--LKDERWSPALTLEQVLLSIQSLLSEPNPE 113

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 J1, J2 and related proteins; The E2J subfamily includes mammalian ubiquitin-conjugating enzymes E2 J1 (UBE2J1/HSPC153/HSPC205/NCUBE1) and J2 (UBE2J2/NCUBE1), yeast ubiquitin-conjugating enzyme E2 6 (UBC6/DOA2), and plant ubiquitin-conjugating enzyme E2 32-34 (UBC32-34). They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2J1 and UBE2J2 are non-canonical ubiquitin-conjugating enzyme (NCUBE), which function in the selective degradation of misfolded membrane proteins from the endoplasmic reticulum (ERAD). Saccharomyces cerevisiae UBC6 functions in degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system. It is a cognate E2 conjugating enzyme for the DOA10 ubiquitin ligase complex, which is part of the ERAD-C pathway responsible for the rapid degradation of membrane proteins with misfolded cytoplasmic domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   5 RGGYYHGKLIFPREFPFKPPSIYMITPNGRFKCNTRLCLSITDFHPDTWNPAWSVSTILTGLLSFMVEKGPT-LGSIETS 83
Cdd:cd23799   43 EGGIYHGKIVFPPDYPFKPPSIYMLTPNGRFETNTKICLSISSFHPESWNPAWSIRTILIGLLSFMPEDEEGaGGSIDTS 122

                         90
                 ....*....|..
gi 767902207  84 DFTKRQLAVQSL 95
Cdd:cd23799  123 DEERRRLAKESR 134

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain/ubiquitin E2 variant (UEV) domain; The family includes ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain and ubiquitin (Ub) E2 variant (UEV) domain. They belong to the ubiquitin-conjugating (UBC) superfamily that represents a structural domain with an alpha-beta(4)-alpha(3) core fold. E2 is part of the ubiquitin-mediated protein degradation pathway in which a thioester linkage forms between a conserved cysteine and the C-terminus of ubiquitin, and complexes with ubiquitin protein ligase enzymes, E3. This pathway regulates many fundamental cellular processes. There are also other E2s which form thioester linkages without the use of E3s. Several UBC homologs (TSG101, Mms2, Croc-1 and similar proteins) contains the UEV domain, which lacks the active site cysteine essential for ubiquitination and appear to function in DNA repair pathways.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PNgrFKCNTRLCLSItdFHPDTWNPAWSVSTILTGLLSFMVE 72
Cdd:cd00195   44 GGVFKLDIEFPDDYPFKPPKVRFLTpiyhPN--VDPDGEICLDI--LKSEGWSPALTLRSVLLSIQSLLSD 110

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of Schizosaccharomyces pombe UBC14 and related proteins; Schizosaccharomyces pombe UBC14 (EC 2.3.2.23), also called ubiquitin-conjugating enzyme E2 14, E2 ubiquitin-conjugating enzyme 14, ubiquitin carrier protein 14, or ubiquitin-protein ligase 14, acts as a ubiquitin-conjugating enzyme that catalyzes the covalent attachment of ubiquitin to other proteins. It mediates the selective degradation of short-lived and abnormal proteins.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PNgrFKCNTRLCLSITDfhPDTWNPAWSVSTILTGLLSFMVEKGPT 76
Cdd:cd23815   44 GGIFKFKITFPEDYPFKPPTVKFTTkiyhPN--VDDDGSICLGILK--SDAWKPSIKLVSVLNALLDLLEEPNPD 114

ubiquitin-conjugating enzyme family protein; This subfamily includes ubiquitin-conjugating enzyme E2, catalytic (UBCc) domains mostly found in non-vertebrate eukaryotes. They belong to the ubiquitin-conjugating (UBC) superfamily that represents a structural domain with an alpha-beta(4)-alpha(3) core fold. E2 is part of the ubiquitin-mediated protein degradation pathway in which a thioester linkage forms between a conserved cysteine and the C-terminus of ubiquitin and complexes with ubiquitin protein ligase enzymes, E3. This pathway regulates many fundamental cellular processes. There are also other E2s which form thioester linkages without the use of E3s.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PNGrFKCNtRLCLSITDFHPDT-------WNPAWSVSTILTGLLSFMVE 72
Cdd:cd23955   43 GVILHLELTFPEDYPNSPPSVRLLTplphPNV-FTGN-YICLDMLENFAKHhskpysgWSPAYTVQSILLQLQAFLFD 118

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin conjugating enzyme E2 E1-E3 and related proteins; The E2E subfamily includes mammalian ubiquitin-conjugating enzyme E2 E1-3 (UBE2E1/UBCH6, UBE2E2/UBCH8, UBE2E3/UBCH9) and similar proteins. UBE2E, also known as (E3-independent) E2 ubiquitin-conjugating enzyme E, or E2 ubiquitin-conjugating enzyme E, accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. UBE2E1 (EC 2.3.2.23 and EC 2.3.2.24) catalyzes the covalent attachment of ISG15 to other proteins. It mediates the selective degradation of short-lived and abnormal proteins. In vitro, it also catalyzes 'Lys-48'-linked polyubiquitination. In vitro, both UBE2E2 (EC 2.3.2.23) and UBE2E3 (EC 2.3.2.23) catalyze 'Lys-11'- and 'Lys-48'-, as well as 'Lys-63'-linked polyubiquitination. UBE2E2 catalyzes the ISGylation of influenza A virus NS1 protein. UBE2E3 participates in the regulation of trans-epithelial sodium transport in renal cells. It may be involved in cell growth arrest.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   2 PAG---RGGYYHGKLIFPREFPFKPPSIYMITPngRFKCNT----RLCLSITDfhpDTWNPAWSVSTILTGLLSFMVE-- 72
Cdd:cd23793   37 PPGsvyEGGVFFLDIHFPPDYPFKPPKVTFRTR--IYHCNInsqgVICLDILK---DNWSPALTISKVLLSICSLLTDcn 111

                         90
                 ....*....|....*...
gi 767902207  73 -KGPTLGSIETSDFTKRQ 89
Cdd:cd23793  112 pADPLVGSIATQYLTDRE 129

ubiquitin E2 variant (UEV) domain of Drosophila melanogaster Morgue and related proteins; Morgue is an F-box/ubiquitin conjugase domain protein important for grim-reaper mediated apoptosis. It contains both an F-box and a UEV domain that is homologous to E2 ubiquitin ligases but lacks the conserved cysteine residue required for catalytic activity.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PNgrFKCNTRLCLSItdFHPDtWNPAWSVSTILTGLLSFM 70
Cdd:cd23826   48 GGIFFLRIQIPESYPFRPPKVRFLTkiyhPN--ISRHGDICLDI--LEHN-WSLALTIEKVLISIQSLL 111

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 L3, L5, L6 and related proteins; The E2L3-like subfamily includes mammalian ubiquitin-conjugating enzymes E2 L3 (UBE2L3/UBCH7/UBCE7), L5 (UBE2L5), L6 (UBE2L6/UBCH8), and similar proteins. They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2L3 specifically acts with HECT-type and RBR family E3 ubiquitin-protein ligases. It does not function with most RING-containing E3 ubiquitin-protein ligases because it lacks intrinsic E3-independent reactivity with lysine: in contrast, it has activity with the RBR family E3 enzymes, such as PRKN and ARIH1, that function like RING-HECT hybrids. In vitro, UBE2L3 catalyzes 'Lys-11'-linked polyubiquitination. It is involved in the selective degradation of short-lived and abnormal proteins. In addition to ubiquitin, UBE2L6 also catalyzes the covalent attachment of ISG15 to other proteins. It functions in the E6/E6-AP-induced ubiquitination of p53/TP53. It promotes ubiquitination and subsequent proteasomal degradation of FLT3.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 767902207  12 KLIFPREFPFKPPSIYMITP--------NGRFkcntrlCLSITdfHPDTWNPAWSVSTILTGLL 67
Cdd:cd23801   52 EITFPAEYPFKPPKITFKTKiyhpnvdeKGQV------CLPII--SPENWKPATKIDQVLQALL 107

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 G1 and related proteins; The subfamily includes mammalian ubiquitin-conjugating enzymes E2 G1 (UBE2G1/UBC7/E217K), fission yeast ubiquitin-conjugating enzyme E2 15 (UBC15), plant ubiquitin-conjugating enzymes E2 7 (UBC7), E2 13 (UBC13) and E2 14 (UBC14). They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. In vitro, UBE2G1 catalyzes 'Lys-48'-, as well as 'Lys-63'-linked polyubiquitination. It may be involved in the degradation of muscle-specific proteins and may mediate polyubiquitination of CYP3A4. Schizosaccharomyces pombe UBC15 has a role in the formation of chromatin structures that influence the localization of transcriptional silencing factors. Arabidopsis thaliana UBC7, UBC13 and UBC14 are involved in the formation of multiubiquitin chains. They signal the protein for selective degradation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT--------PNGrfkcntRLCLSItdFHP------------DTWNPAWSVSTILTG 65
Cdd:cd23795   48 GGFFKAELTFPDDYPNSPPKMKFITemwhpnvyPDG------DVCISI--LHPpgedkngyekasERWLPIHTVETILIS 119

                 ....*..
gi 767902207  66 LLSFMVE 72
Cdd:cd23795  120 VISMLSD 126

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin conjugating enzyme E2 T and related enzymes; The E2T subfamily includes mammalian ubiquitin-conjugating enzymes E2 T (UBE2T/HSPC150/PIG50), plant ubiquitin-conjugating enzyme E2 37 (UBC37), and similar proteins. They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2T, also called cell proliferation-inducing gene 50 protein, catalyzes monoubiquitination. It is involved in mitomycin-C (MMC)-induced DNA repair. It acts as a specific E2 ubiquitin-conjugating enzyme for the Fanconi anemia complex by associating with E3 ubiquitin-protein ligase FANCL and catalyzing monoubiquitination of FANCD2, a key step in the DNA damage pathway. UBE2T also mediates monoubiquitination of FANCL and FANCI. It may contribute to ubiquitination and degradation of BRCA1. In vitro, UBE2T can promote polyubiquitination using all 7 ubiquitin Lys residues, but may prefer 'Lys-11'-, 'Lys-27'-, 'Lys-48'- and 'Lys-63'-linked polyubiquitination.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMITP--------NGrfkcntRLCLSITDFHP-DTWNPAWSVSTILTGLLSFMVEKGP 75
Cdd:cd23805   44 GGVFKLEITIPERYPFEPPKVRFLTPiyhpnidsAG------RICLDILKMPPkGSWKPSLNISTVLTSIRLLLAEPNP 116

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 I and related proteins; The E2I subfamily includes mammalian ubiquitin-conjugating enzymes E2 I (UBE2I/UBC9/UBCE9, EC 2.3.2.-), yeast ubiquitin-conjugating enzyme E2-18 kDa (UBC9, EC2.3.2.-), and plant SUMO-conjugating enzyme 1 (SCE1/AHUS5, EC2.3.2.-). UBE2I, also called SUMO-conjugating enzyme UBC9, RING-type E3 SUMO transferase UBC9, SUMO-protein ligase, ubiquitin carrier protein 9, ubiquitin carrier protein I, or ubiquitin-protein ligase I, accepts the ubiquitin-like proteins SUMO1, SUMO2, SUMO3, SUMO4 and SUMO1P1/SUMO5 from the UBLE1A-UBLE1B E1 complex and catalyzes their covalent attachment to other proteins with the help of an E3 ligase such as RANBP2, CBX4 and ZNF451. It can catalyze the formation of poly-SUMO chains. It is necessary for sumoylation of FOXL2 and KAT5 and essential for nuclear architecture and chromosome segregation. UBE2I also sumoylates p53/TP53 at 'Lys-386' and mediates sumoylation of ERCC6 which is essential for its transcription-coupled nucleotide excision repair activity. Saccharomyces cerevisiae UBC9, also called SUMO-conjugating enzyme UBC9, RING-type E3 SUMO transferase UBC9, ubiquitin carrier protein 9, ubiquitin-conjugating enzyme E2-18 kDa, acts as an E2 ubiquitin-like--protein ligase that mediates SUMO/Smt3 attachment to septins and PCNA. It may be involved in degradation of S- (CLB5) and M-phase cyclins (CLB2). Arabidopsis thaliana SCE1, also called SUMO-conjugating enzyme SCE1, protein EMBRYO DEFECTIVE 1637, or protein hus5 homolog, is a SUMO-conjugating enzyme that accepts the SUMO proteins from the E1 SUMO-activating heterodimer SAE1/SAE2 and catalyzes its covalent attachment to other proteins with the E3 SUMO ligases SIZ1 and MMS21. It associates with SIZ1 for sumoylation of the transcription factor GTE3.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT--------PNGrfkcntRLCLSITDfHPDTWNPAWSVSTILTGL 66
Cdd:cd23798   52 GGLYKLTMEFPEDYPSKPPKCKFDPplfhpnvyPSG------TVCLSILN-EDKDWKPSITIKQILLGI 113

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin conjugating enzymes E2 F, E2 M and related proteins; The E2F/E2M subfamily includes mammalian ubiquitin-conjugating enzymes E2 F (UBE2F/NCE2, EC 2.3.2.32) and E2 M (UBE2M/UBC12, EC 2.3.2.34), yeast NEDD8-conjugating enzyme UBC12 (EC 2.3.2.24), plant RUB1-conjugating enzyme 1-2 (RCE1/UBC12 and RCE2/UBC12L, EC 2.3.2.-), and similar proteins. UBE2F (also called EDD8-conjugating enzyme UBE2F, NEDD8 carrier protein UBE2F, NEDD8 protein ligase UBE2F, NEDD8-conjugating enzyme 2, or RING-type E3 NEDD8 transferase UBE2F) and UBE2M (also called NEDD8-conjugating enzyme UBC12, or NEDD8 carrier protein) accept the ubiquitin-like protein NEDD8 from the UBA3-NAE1 E1 complex and catalyzes its covalent attachment to other proteins. The RBX2-UBE2F complex neddylates specific target proteins, such as CUL5. The RBX1-UBE2M complex neddylates specific target proteins, such as CUL1, CUL2, CUL3 and CUL4. UBE2M is involved in cell proliferation. Saccharomyces cerevisiae UBC12 and Arabidopsis thaliana RCE1/RCE2 accept the ubiquitin-like protein NEDD8/RUB1 from the UBA3-ULA1 E1 complex and the ECR1-AXR1 E1 complex, respectively.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   7 GYYHG-----KLIFPREFPFKPPSIymitpngrfKCNTRL-----------CLSITDFHpdtWNPAWSVSTILTGLLSFM 70
Cdd:cd23794   41 GYYKGgtfvfEIDIPDNYPFEPPKV---------KCLTKIyhpnideegnvCLNILRED---WKPVLSLKDVILGLLFLF 108

                 ..
gi 767902207  71 VE 72
Cdd:cd23794  109 LE 110

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 G2 and related proteins; The subfamily includes mammalian ubiquitin-conjugating enzymes E2 G2 (UBE2G2/UBC7), yeast E2 ubiquitin-conjugating enzyme 7 (UBC7) and similar proteins. They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. In vitro, UBE2G2 catalyzes 'Lys-48'-linked polyubiquitination. It is involved in endoplasmic reticulum-associated degradation (ERAD) and is required for sterol-induced ubiquitination of 3-hydroxy-3-methylglutaryl coenzyme A reductase and its subsequent proteasomal degradation. UBC7, also called ubiquitin-conjugating enzyme E2-18 kDa, functions in the degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYM--------ITPNGrfkcntRLCLSItdFHPDT------------WNPAWSVSTILTG 65
Cdd:cd23796   46 GGVFPARLTFPKDYPLSPPKMKFtcemfhpnIYPDG------RVCISI--LHAPGddpmgyessserWSPVQSVEKILLS 117

                 ....*..
gi 767902207  66 LLSFMVE 72
Cdd:cd23796  118 VVSMLAE 124

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin-conjugating enzyme E2 K and related proteins; The E2J subfamily includes mammalian ubiquitin-conjugating enzymes E2 K (UBE2K/HIP2/LIG), yeast ubiquitin-conjugating enzyme E2 1 (UBC1), and plant ubiquitin-conjugating enzyme E2 27 (UBC27). They are ubiquitin-conjugating enzymes (EC 2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2K is also called huntingtin-interacting protein 2 (HIP-2), ubiquitin-conjugating enzyme E2-25 kDa, or ubiquitin-conjugating enzyme E2(25K). In vitro, in the presence or absence of BRCA1-BARD1 E3 ubiquitin-protein ligase complex, UBE2K catalyzes the synthesis of 'Lys-48'-linked polyubiquitin chains. It does not transfer ubiquitin directly, but elongates monoubiquitinated substrate proteins. Saccharomyces cerevisiae UBC1, also called ubiquitin-conjugating enzyme E2-24 kDa, functions in the degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system. It is a cognate E2 conjugating enzyme for the HRD1 ubiquitin ligase complex, which is part of the ERAD-L and ERAD-M pathways responsible for the rapid degradation of soluble lumenal and membrane proteins with misfolded lumenal domains (ERAD-L), or ER-membrane proteins with misfolded transmembrane domains (ERAD-M).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PN-----GrfkcntRLCLSITDfhpDTWNPAWsvsTILTGLLS 68
Cdd:cd23800   47 GGTFVLDIKIPDTYPFEPPKMKFITkiwhPNissqtG------AICLDILK---DQWSPAL---TLRTALLS 106

ubiquitin-conjugating enzyme; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PNgrFKCNTRLCLSITDfhpDTWNPAWSVSTIL 63
Cdd:PTZ00390  48 GGYYKLELFLPEQYPMEPPKVRFLTkiyhPN--IDKLGRICLDILK---DKWSPALQIRTVL 104

Ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain of ubiquitin conjugating enzyme E2 S and related domains; The E2S subfamily includes mammalian ubiquitin-conjugating enzymes E2 S (UBE2S/E2EPF), plant ubiquitin-conjugating enzyme E2 22 (UBC22), and similar proteins. They are ubiquitin-conjugating enzymes (EC2.3.2.23) that accept ubiquitin from the E1 complex and catalyze the covalent attachment to other proteins. UBE2S catalyzes 'Lys-11'-linked polyubiquitination. It acts as an essential factor of the anaphase promoting complex/cyclosome (APC/C), a cell cycle-regulated ubiquitin ligase that controls progression through mitosis. UBE2S acts by specifically elongating 'Lys-11'-linked polyubiquitin chains initiated by the E2 enzyme UBE2C/UBCH10 on APC/C substrates, enhancing the degradation of APC/C substrates by the proteasome and promoting mitotic exit. It also acts by elongating ubiquitin chains initiated by the E2 enzyme UBE2D1/UBCH5 in vitro; it is however unclear whether UBE2D1/UBCH5 acts as an E2 enzyme for the APC/C in vivo. UBE2S is also involved in ubiquitination and subsequent degradation of VHL, resulting in an accumulation of HIF1A. In vitro, it can promote polyubiquitination using all 7 ubiquitin Lys residues, except 'Lys-48'-linked polyubiquitination.

                         10        20        30
                 ....*....|....*....|....*....|.
gi 767902207   6 GGYYHGKLIFPREFPFKPPSIYMIT----PN 32
Cdd:cd23804   48 GGVFRVKLVLGPDFPASPPKGYFLTkifhPN 78