RING finger found in polycomb group RING finger protein 3 (PCGF3) and similar proteins; PCGF3, also known as RING finger protein 3A (RNF3A), is one of six PcG RING finger (PCGF) homologs (PCGF1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6) and serves as the core component of a Polycomb repressive complex 1 (PRC1). Like other PCGF homologs, PCGF3 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. PCGF3 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1907166055   4 RKIKLWDINAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQYIG 69
Cdd:cd16735     1 RKIRLKDLNAHITCRLCKGYLIDATTITECLHTFCKSCLVKYLEENNTCPTCGIVIHQSHPLQYIG 66

RING finger found in polycomb group RING finger protein 3 (PCGF3) and similar proteins; PCGF3, also known as RING finger protein 3A (RNF3A), is one of six PcG RING finger (PCGF) homologs (PCGF1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6) and serves as the core component of a Polycomb repressive complex 1 (PRC1). Like other PCGF homologs, PCGF3 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. PCGF3 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1907166055   4 RKIKLWDINAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQYIG 69
Cdd:cd16735     1 RKIRLKDLNAHITCRLCKGYLIDATTITECLHTFCKSCLVKYLEENNTCPTCGIVIHQSHPLQYIG 66

Zinc finger, C3HC4 type (RING finger); The C3HC4 type zinc-finger (RING finger) is a cysteine-rich domain of 40 to 60 residues that coordinates two zinc ions, and has the consensus sequence: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C where X is any amino acid. Many proteins containing a RING finger play a key role in the ubiquitination pathway.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1907166055  17 CRLCSGYLIDATTVTECLHTFCRSCLVKYLEENN-TCPTC 55
Cdd:pfam00097   1 CPICLEEPKDPVTLLPCGHLFCSKCIRSWLESGNvTCPLC 40

DNA repair protein rad18; All proteins in this family for which functions are known are involved in nucleotide excision repair.This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University). [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1907166055  17 CRLCSGYLiDATTVTECLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:TIGR00599  29 CHICKDFF-DVPVLTSCSHTFCSLCIRRCLSNQPKCPLCR 67

RING finger found in polycomb group RING finger protein 3 (PCGF3) and similar proteins; PCGF3, also known as RING finger protein 3A (RNF3A), is one of six PcG RING finger (PCGF) homologs (PCGF1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6) and serves as the core component of a Polycomb repressive complex 1 (PRC1). Like other PCGF homologs, PCGF3 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. PCGF3 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1907166055   4 RKIKLWDINAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQYIG 69
Cdd:cd16735     1 RKIRLKDLNAHITCRLCKGYLIDATTITECLHTFCKSCLVKYLEENNTCPTCGIVIHQSHPLQYIG 66

RING finger found in polycomb group RING finger protein 4 (PCGF4) and similar proteins; PCGF4, also known as polycomb complex protein BMI-1 (B cell-specific Moloney murine leukemia virus integration site 1) or RING finger protein 51 (RNF51), is one of six PcG RING finger (PCGF) homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR). It serves as the core component of a canonical Polycomb repressive complex 1 (PRC1), which is composed of a chromodomain-containing protein (CBX2, CBX4, CBX6, CBX7 or CBX8) and a Polyhomeotic protein (PHC1, PHC2, or PHC3), and plays important roles in chromatin compaction and H2AK119 monoubiquitination. PCGF4 associates with the Runx1/CBFbeta transcription factor complex to silence target genes in a PRC2-independent manner. Moreover, PCGF4 is expressed in the hair cells and supporting cells. It can regulate cell survival by controlling mitochondrial function and reactive oxygen species (ROS) level in thymocytes and neurons, thus having an important role in the survival and sensitivity to ototoxic drug of auditory hair cells. Furthermore, PCGF4 controls memory CD4 T-cell survival through direct repression of Noxa gene in an Ink4a- and Arf-independent manner. It is required in neurons to suppress p53-induced apoptosis via regulating the antioxidant defensive response, and also involved in the tumorigenesis of various cancer types. PCGF4 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907166055   5 KIKLWDINAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQYIGHDRTMQDIVYKLVPG 84
Cdd:cd16736     2 RIKITELNPHLMCVLCGGYFIDATTIIECLHSFCKTCIVRYLETSKYCPICDVQVHKTRPLLNIRSDKTLQDIVYKLVPG 81

                          90
                  ....*....|...
gi 1907166055  85 LQEAEMRKQREFY 97
Cdd:cd16736    82 LFKNEMKRRRDFY 94

RING finger found in polycomb group RING finger protein 2 (PCGF2) and similar proteins; PCGF2, also known as DNA-binding protein Mel-18, RING finger protein 110 (RNF110), or zinc finger protein 144 (ZNF144), is one of six PcG RING finger (PCGF) homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR). It serves as the core component of a canonical Polycomb repressive complex 1 (PRC1), which is composed of a chromodomain-containing protein (CBX2, CBX4, CBX6, CBX7 or CBX8) and a Polyhomeotic protein (PHC1, PHC2, or PHC3). Like other PCGF homologs, PCGF2 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. Moreover, PCGF2 uniquely regulates PRC1 to specify mesoderm cell fate in embryonic stem cells. It is required for PRC1 stability and maintenance of gene repression in embryonic stem cells (ESCs) and essential for ESC differentiation into early cardiac-mesoderm precursors. PCGF2 also plays a significant role in the angiogenic function of endothelial cells (ECs) by regulating endothelial gene expression. Furthermore, PCGF2 is a SUMO-dependent regulator of hormone receptors. It facilitates the deSUMOylation process by inhibiting PCGF4/BMI1-mediated ubiquitin-proteasomal degradation of SUMO1/sentrin-specific protease 1 (SENP1). It is also a novel negative regulator of breast cancer stem cells (CSCs) that inhibits the stem cell population and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling. PCGF2 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1907166055   3 TRKIKLWDINAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQYIGHDRTMQDIVYK 80
Cdd:cd16734     3 TTRIKITELNPHLMCALCGGYFIDAATIVECLHSFCKTCIVRYLETNKYCPMCDVQVHKTRPLLSIRSDKTLQDIVYK 80

RING finger- and WD40-associated ubiquitin-like (RAWUL) domain found in polycomb group RING finger protein 5 (PCGF5) and similar proteins; PCGF5, also termed RING finger protein 159 (RNF159), is one of six PcG RING finger (PCGF) homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR) and serves as the core component of a Polycomb repressive complex 1 (PRC1). Like other PCGF homologs, PCGF5 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. PCGF5 contains a C3HC4-type RING-HC finger, and a RAWUL domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907166055 151 DEQVSICLECNS-------SKLRGLKRKWIRCSAQATVLHLKKFIAKKLNLSSFNELDILCNEEILGKDHTLKFVVVTRW 223
Cdd:cd17084     1 DPQIAICLDCLRnngqsgdNVVKGLMKKFIRCSSRVTVGTIKKFLSLKLKLPSSYELDVLCNGEIMGKDHTLEFIYMTRW 80

                  ...
gi 1907166055 224 RFK 226
Cdd:cd17084    81 RLR 83

RING finger, HC subclass, found in Polycomb Group RING finger homologs (PCGF1, 2, 3, 4, 5 and 6), and similar proteins; This subfamily includes six Polycomb Group (PcG) RING finger homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR) that use epigenetic mechanisms to maintain or repress expression of their target genes. They were first discovered in fruit flies and are well known for silencing Hox genes through modulation of chromatin structure during embryonic development. PCGF homologs play important roles in cell proliferation, differentiation, and tumorigenesis. They all have been found to associate with ring finger protein 2 (RNF2). The RNF2-PCGF heterodimer is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. Moreover, PCGF homologs are critical components in the assembly of distinct Polycomb Repression Complex 1 (PRC1) related complexes which is involved in the maintenance of gene repression and which target different genes through distinct mechanisms. The Drosophila PRC1 core complex is formed by the Polycomb (Pc), Polyhomeotic (Ph), Posterior sex combs (Psc), and Sex combs extra (Sce, also known as Ring) subunits. In mammals, the composition of PRC1 is much more diverse and varies depending on the cellular context. All PRC1 complexes contain homologs of the Drosophila Ring protein. Ring1A/RNF1 and Ring1B/RNF2 are E3 ubiquitin ligases that mark lysine 119 of histone H2A with a single ubiquitin group (H2AK119ub). Mammalian homologs of the Drosophila Psc protein, such as PCGF2/Mel-18 or PCGF4/BMI1, regulate PRC1 enzymatic activity. PRC1 complexes can be divided into at least two classes according to the presence or absence of CBX proteins, which are homologs of Drosophila Pc. Canonical PRC1 complexes contain CBX proteins that recognize and bind H3K27me3, the mark deposited by PRC2. Therefore, canonical PRC1 complexes and PRC2 can act together to repress gene transcription and maintain this repression through cell division. Non-canonical PRC1 complexes, containing RYBP (together with additional proteins, such as L3mbtl2 or Kdm2b) rather than the CBX proteins have recently been described in mammals. PCGF homologs contain a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1907166055  15 ITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd16525     1 LTCSLCKGYLIDATTITECLHSFCKSCIVRHLETSKNCPVCD 42

RAWUL domain RING finger- and WD40-associated ubiquitin-like; The RAWUL domain is found at the C-terminus of poly-comb group RING finger proteins. It is a ubiquitin-like domain. RAWUL binds directly to PUFD, a domain on BCOR proteins (BCL6 corepressor). BCOR has emerged as an important player in development and health.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1907166055 171 KWIRCSAQATVLHLKKFIAKKLNLSSFNE--LDILCNEEILGKDHTLKFVVVTRWR 224
Cdd:pfam16207   1 RYLKCPANATVDHLKKYLAMKLGLELQNEyiVEILYNGEPLPDSYTLDVAYIKYWK 56

RING finger, HC subclass, found in really interesting new gene proteins RING1, RING2 and similar proteins; RING1, also known as polycomb complex protein RING1, RING finger protein 1 (RNF1), or RING finger protein 1A (RING1A), is a transcriptional repressor that is associated with the Polycomb group (PcG) protein complex involved in stable repression of gene activity. RING2, also known as huntingtin-interacting protein 2-interacting protein 3, HIP2-interacting protein 3, protein DinG, RING finger protein 1B (RING1B), RING finger protein 2 (RNF2), or RING finger protein BAP-1, is an E3 ubiquitin-protein ligase that interacts with both nucleosomal DNA and an acidic patch on histone H4 to achieve the specific monoubiquitination of K119 on histone H2A (H2AK119ub), thereby playing a central role in histone code and gene regulation. Both RING1 and RING2 are core components of polycomb repressive complex 1 (PRC1) that functions as an E3-ubuiquitin ligase transferring the mono-ubuiquitin mark to the C-terminal tail of Histone H2A at K118/K119. PRC1 is also capable of chromatin compaction, a function not requiring histone tails, and this activity appears important in gene silencing. RING2 acts as the main E3 ubiquitin ligase on histone H2A of the PRC1 complex, while RING1 may rather act as a modulator of RNF2/RING2 activity. Members of this family contain a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1907166055  15 ITCRLCSGYLIDATTVTECLHTFCRSCLVKYLEE-NNTCPTCRI 57
Cdd:cd16531     2 LMCPICLGIIKNTMTVKECLHRFCAECIEKALRLgNKECPTCRK 45

RING finger, HC subclass, found in checkpoint with forkhead and RING finger domains protein (CHFR); CHFR, also known as RING finger protein 196 (RNF196), is a checkpoint protein that delays entry into mitosis in response to stress. It functions as an E3 ubiquitin ligase that ubiquitinates and degrades its target proteins, such as Aurora-A, Plk1, Kif22, and PARP-1, which are critical for proper mitotic transitions. It also plays an important role in cell cycle progression and tumor suppression, and is negatively regulated by SUMOylation-mediated proteasomal ubiquitylation. Moreover, CHFR is involved in the early stage of the DNA damage response, which mediates the crosstalk between ubiquitination and poly-ADP-ribosylation. CHFR contains a fork head associated (FHA) domain and a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1907166055  14 HITCRLCSGYLIDATTVTECLHTFCRSCLVKYLE-ENNTCPTCR 56
Cdd:cd16503     2 NLTCSICQDLLHDCVSLQPCMHNFCAACYSDWMErSNTECPTCR 45

second RING finger, HC subclass, found in the LON peptidase N-terminal domain and RING finger protein family; The LON peptidase N-terminal domain and RING finger protein family includes LONRF1 (also known as RING finger protein 191 or RNF191), LONRF2 (also known as RING finger protein 192, RNF192, or neuroblastoma apoptosis-related protease), LONRF3 (also known as RING finger protein 127 or RNF127), which are characterized by containing two C3HC4-type RING-HC fingers, four tetratricopeptide (TPR) repeats, and an ATP-dependent protease La (LON) substrate-binding domain at the C-terminus. Their biological functions remain unclear. This model corresponds to the second RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1907166055  17 CRLCSGYLIDATTvTECLHTFCRSCLVKYLEENNTCPTCRIVI 59
Cdd:cd16514     4 CSLCLRLLYEPVT-TPCGHTFCRACLERCLDHSPKCPLCRTSL 45

RING finger, HC subclass, found in tripartite motif-containing protein 10 (TRIM10) and similar proteins; TRIM10, also known as B30-RING finger protein (RFB30), RING finger protein 9 (RNF9), or hematopoietic RING finger 1 (HERF1), is a novel hematopoiesis-specific RING finger protein required for terminal differentiation of erythroid cells. TRIM10 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1907166055  10 DINAHITCRLCSGYLIDATTVtECLHTFCRSCLVKYLEENN-------TCPTCR 56
Cdd:cd16593     1 SLADEVNCPICQGTLREPVTI-DCGHNFCRACLTRYCEIPGpdleeppTCPLCK 53

RING finger, HC subclass, found in postreplication repair protein RAD18 and similar proteins; RAD18, also known as HR18 or RING finger protein 73 (RNF73), is an E3 ubiquitin-protein ligase involved in post replication repair of UV-damaged DNA via its recruitment to stalled replication forks. It associates to the E2 ubiquitin conjugating enzyme UBE2B to form the UBE2B-RAD18 ubiquitin ligase complex involved in mono-ubiquitination of DNA-associated PCNA on K164. It also interacts with another E2 ubiquitin conjugating enzyme RAD6 to form a complex that monoubiquitinates proliferating cell nuclear antigen at stalled replication forks in DNA translesion synthesis. Moreover, Rad18 is a key factor in double-strand break DNA damage response (DDR) pathways via its association with K63-linked polyubiquitylated chromatin proteins. It can function as a mediator for DNA damage response signals to activate the G2/M checkpoint in order to maintain genome integrity and cell survival after ionizing radiation (IR) exposure. RAD18 contains a C3HC4-type RING-HC finger, a ubiquitin-binding zinc finger domain (UBZ), a SAP (SAF-A/B, Acinus and PIAS) domain, and a RAD6-binding domain (R6BD).

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1907166055  17 CRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSH 63
Cdd:cd16529     7 CPICFEYFNTAMMITQCSHNYCSLCIRRFLSYKTQCPTCRAAVTESD 53

RING finger- and WD40-associated ubiquitin-like (RAWUL) domain found in polycomb group RING finger protein 4 (PCGF4); PCGF4, also termed polycomb complex protein BMI-1 (B cell-specific Moloney murine leukemia virus integration site 1), or RING finger protein 51 (RNF51), is one of six PcG RING finger (PCGF) homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR) and serves as the core component of a canonical Polycomb repressive complex 1 (PRC1), which is composed of a chromodomain-containing protein (CBX2, CBX4, CBX6, CBX7 or CBX8) and a Polyhomeotic protein (PHC1, PHC2, or PHC3), and plays important roles in chromatin compaction and H2AK119 monoubiquitination. PCGF4 associates with the Runx1/CBFbeta transcription factor complex to silence target gene in a PRC2-independent manner. Moreover, PCGF4 is expressed in the hair cells and supporting cells. It can regulate cell survival by controlling mitochondrial function and reactive oxygen species (ROS) level in thymocytes and neurons, thus having an important role in the survival and sensitivity to ototoxic drug of auditory hair cells. Furthermore, PCGF4 controls memory CD4 T-cell survival through direct repression of Noxa gene in an Ink4a- and Arf-independent manner. It is required in neurons to suppress p53-induced apoptosis via regulating the antioxidant defensive response, and also involved in the tumorigenesis of various cancer types. PCGF4 contains a C3HC4-type RING-HC finger, and a RAWUL domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907166055 140 KQEEDNDYHRSDEQVSiclecnssklrglKRKWIRCSAQATVLHLKKFIAKKLNLSSFNELDILCNEEILGKDHTL-KFV 218
Cdd:cd17165    15 ERKGNKDKEKSKEEVN-------------DKRYLRCPAAMTVMHLRKFLRSKMDIPSTFQIDVMYEEEPLKDYYTLmDIA 81

                  ....*.
gi 1907166055 219 VVTRWR 224
Cdd:cd17165    82 YIYTWR 87

Variant RING finger, HC subclass (C4C4-type), found in retinoblastoma-binding protein 6 (RBBP6) and similar proteins; RBBP6, also known as proliferation potential-related protein, protein P2P-R, retinoblastoma-binding Q protein 1 (RBQ-1), or p53-associated cellular protein of testis (PACT), is a nuclear E3 ubiquitin-protein ligase involved in multiple processes, such as the control of gene expression, mitosis, cell differentiation, and cell apoptosis. It plays a role in both promoting and inhibiting apoptosis in many human cancers, including esophageal, lung, hepatocellular, and colon cancers, familial myeloproliferative neoplasms, as well as in human immunodeficiency virus-associated nephropathy (HIVAN). It functions as an Rb- and p53-binding protein that plays an important role in chaperone-mediated ubiquitination and possibly in protein quality control. It acts as a scaffold protein to promote the assembly of the p53/TP53-MDM2 complex, resulting in an increase of MDM2-mediated ubiquitination and degradation of p53/TP53, and leading to both apoptosis and cell growth. It is also a double-stranded RNA-binding protein that plays a role in mRNA processing by regulating the human polyadenylation machinery and modulating expression of mRNAs with AU-rich 3' untranslated regions (UTRs). Moreover, RBBP6 ubiquitinates and destabilizes the transcriptional repressor ZBTB38 that negatively regulates transcription and levels of the MCM10 replication factor on chromatin. Furthermore, RBBP6 is involved in tunicamycin-induced apoptosis by mediating protein kinase (PKR) activation. RBBP6 contains an N-terminal ubiquitin-like domain and a C4C4-type RING finger, whose overall folding is similar to that of the typical C3HC4-type RING-HC finger. RBBP6 interacts with chaperones Hsp70 and Hsp40 through its N-terminal ubiquitin-like domain. It promotes the ubiquitination of p53 by Hdm2 in an E4-like manner through its RING finger. It also interacts directly with the pro-proliferative transcription factor Y-box-binding protein-1 (YB-1) via its RING finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1907166055  16 TCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENN-TCPTCR 56
Cdd:cd16620     5 KCPICKDLMKDAVLTPCCGNSFCDECIRTALLEEDfTCPTCK 46

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Deltex3 (DTX3) and similar proteins; DTX3, also known as RING finger protein 154 (RNF154), is an E3 ubiquitin-protein ligase that belongs to the Deltex (DTX) family. In contrast to other DTXs, DTX3 does not contain two N-terminal Notch-binding WWE domains, but a short unique N-terminal domain, suggesting it does not interact with the intracellular domain of Notch. Its C-terminal region includes a C3HC4-type RING-HC finger, and a previously unidentified C-terminal domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1907166055  16 TCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQ 61
Cdd:cd16711     3 TCPICLGEIQNKKTLDKCKHSFCEDCITRALQVKKACPMCGEFYGQ 48

HC subclass of RING (RING-HC) finger and its variants; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers. Some have a different Cys/His pattern. Some lack a single Cys or His residue at typical Zn ligand positions, especially, the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can chelate Zn in a RING finger as well. This family corresponds to the HC subclass of RING (RING-HC) fingers that are characterized by containing C3HC4-type canonical RING-HC fingers or noncanonical RING-HC finger variants, including C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type modified RING-HC fingers. The canonical RING-HC finger has been defined as C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C. It binds two Zn ions in a unique "cross-brace" arrangement, which distinguishes it from tandem zinc fingers and other similar motifs. RING-HC fingers can be found in a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle, and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serve as scaffolds for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enables efficient transfer of ubiquitin from E2 to the substrates.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1907166055  16 TCRLCSGYLIDaTTVTECLHTFCRSCLVKYLEENN-TCPTC 55
Cdd:cd16449     2 ECPICLERLKD-PVLLPCGHVFCRECIRRLLESGSiKCPIC 41

RING finger, HC subclass, found in constitutive photomorphogenesis protein 1 (COP1) and similar proteins; COP1, also known as RING finger and WD repeat domain protein 2 (RFWD2) or RING finger protein 200 (RNF200), is a central regulator of photomorphogenic development in plants, which targets key transcription factors for proteasome-dependent degradation. It is localized predominantly in the nucleus, but may also be present in the cytosol. Mammalian COP1 functions as an E3 ubiquitin-protein ligase that interacts with Jun transcription factors and modulates their transcriptional activity. It also interacts with and negatively regulates the tumor-suppressor protein p53. Moreover, COP1 associates with COP9 signalosome subunit 6 (CSN6), and is involved in 14-3-3sigma ubiquitin-mediated degradation. The CSN6-COP1 link enhances ubiquitin-mediated degradation of p27(Kip1), a critical CDK inhibitor involved in cell cycle regulation, to promote cancer cell growth. Furthermore, COP1 functions as the negative regulator of ETV1 and influences prognosis in triple-negative breast cancer. COP1 contains an N-terminal extension, a C3HC4-type RING-HC finger, a coiled coil domain, and seven WD40 repeats. In human COP1, a classic leucine-rich NES, and a novel bipartite NLS is bridged by the RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1907166055  15 ITCRLCSGyLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVI 59
Cdd:cd16504     3 FLCPICFD-IIKEAFVTKCGHSFCYKCIVKHLEQKNRCPKCNFYL 46

RING finger, HC subclass, found in tripartite motif-containing proteins, TRIM7, TRIM11 and TRIM27, and similar proteins; TRIM7, TRIM11 and TRIM27, closely related tripartite motif-containing proteins, belong to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM7, also known as glycogenin-interacting protein (GNIP) or RING finger protein 90 (RNF90), is an E3 ubiquitin-protein ligase that mediates c-Jun/AP-1 activation by Ras signalling. Its phosphorylation and activation by MSK1 in response to direct activation by the Ras-Raf-MEK-ERK pathway can stimulate TRIM7 E3 ubiquitin ligase activity in mediating Lys63-linked ubiquitination of the AP-1 coactivator RACO-1, leading to RACO-1 protein stabilization. Moreover, TRIM7 binds and activates glycogenin, the self-glucosylating initiator of glycogen biosynthesis. TRIM11, also known as protein BIA1, or RING finger protein 92 (RNF92), is an E3 ubiquitin-protein ligase involved in the development of the central nervous system. It is overexpressed in high-grade gliomas and promotes proliferation, invasion, migration and glial tumor growth. TRIM11 acts as a potential therapeutic target for congenital central hypoventilation syndrome (CCHS) by mediating the degradation of CCHS-associated polyalanine-expanded Phox2b. TRIM11 modulates the function of neurogenic transcription factor Pax6 through the ubiquitin-proteosome system, and thus plays an essential role for Pax6-dependent neurogenesis. It also binds to and destabilizes a key component of the activator-mediated cofactor complex (ARC105), humanin, a neuroprotective peptide against Alzheimer's disease-relevant insults, and further regulates ARC105 function in transforming growth factor beta (TGFbeta) signaling. Moreover, TRIM11 negatively regulates retinoic acid-inducible gene-I (RIG-I)-mediated interferon-beta (IFNbeta) production and antiviral activity by targeting TANK-binding kinase-1 (TBK1). It may contribute to the endogenous restriction of retroviruses in cells. It enhances N-tropic murine leukemia virus (N-MLV) entry by interfering with Ref1 restriction. It also suppresses the early steps of human immunodeficiency virus HIV-1 transduction, resulting in decreased reverse transcripts. TRIM27, also known as RING finger protein 76 (RNF76), RET finger protein (RFP), or zinc finger protein RFP, is a nuclear E3 ubiquitin-protein ligase that is highly expressed in testis and in various tumor cell lines. Expression of TRIM27 is associated with prognosis of colon and endometrial cancers. TRIM27 was first identified as a fusion partner of the RET receptor tyrosine kinase. It functions as a transcriptional repressor and associates with several proteins involved in transcriptional activity, such as enhancer of polycomb 1 (Epc1), a member of the Polycomb group proteins, and Mi-2beta, a main component of the nucleosome remodeling and deacetylase (NuRD) complex, and the cell cycle regulator retinoblastoma protein (RB1). It also interacts with HDAC1, leading to downregulation of thioredoxin binding protein 2 (TBP-2), which inhibits the function of thioredoxin. Moreover, TRIM27 mediates Pax7-induced ubiquitination of MyoD in skeletal muscle atrophy. In addition, it inhibits muscle differentiation by modulating serum response factor (SRF) and Epc1. TRIM27 promotes a non-canonical polyubiquitination of PTEN, a lipid phosphatase that catalyzes PtdIns(3,4,5)P3 (PIP3) to PtdIns(4,5)P2 (PIP2). It is an IKKepsilon-interacting protein that regulates IkappaB kinase (IKK) function and negatively regulates signaling involved in the antiviral response and inflammation. TRIM27 also forms a protein complex with MBD4 or MBD2 or MBD3, and thus plays an important role in the enhancement of transcriptional repression through MBD proteins in tumorigenesis, spermatogenesis, and embryogenesis. It is a component of an estrogen receptor 1 (ESR1) regulatory complex that is involved in estrogen receptor-mediated transcription in MCF-7 cells.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1907166055  15 ITCRLCSGYLIDATTvTECLHTFCRSCLVKYLEENNT---CPTCR 56
Cdd:cd16594     6 LTCPICLDYFTDPVT-LDCGHSFCRACIARCWEEPETsasCPQCR 49

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Deltex3 (DTX3), Deltex-3-like (DTX3L) and similar proteins; This subfamily contains Deltex3 (DTX3) and Deltex-3-like (DTX3L), both of which are E3 ubiquitin-protein ligases belonging to the Deltex (DTX) family. DTX3, also known as RING finger protein 154 (RNF154), has a biological function that remains unclear. DTX3L, also known as B-lymphoma- and BAL-associated protein (BBAP) or Rhysin-2 (Rhysin2), regulates endosomal sorting of the G protein-coupled receptor CXCR4 from endosomes to lysosomes. It also regulates subcellular localization of its partner protein, B aggressive lymphoma (BAL), by a dynamic nucleocytoplasmic trafficking mechanism. In contrast to other DTXs, both DTX3 and DTX3L contain a C3HC4-type RING-HC finger, and a previously unidentified C-terminal domain. DTX3L can associate with DTX1 through its unique N termini and further enhance self-ubiquitination.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1907166055  16 TCRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIV 58
Cdd:cd16506     2 TCPICLDEIQNKKTLEKCKHSFCEDCIDRALQVKPVCPVCGVV 44

RING finger, HC subclass, found in Saccharomyces cerevisiae DNA repair protein RAD16, Schizosaccharomyces pombe rhp16, and similar proteins; Budding yeast RAD16, also known as ATP-dependent helicase RAD16, is encoded by a yeast excision repair gene homologous to the recombinational repair gene RAD54 and to the SNF2 gene involved in transcriptional activation. It is a component of the global genome repair (GGR) complex that promotes global genome nucleotide excision repair (GG-NER) by removing DNA damage from non-transcribing DNA. RAD16 is involved in differential repair of DNA after UV damage, and repairs preferentially the MAT-alpha locus compared with the HML-alpha locus. Fission yeast rhp16, also known as ATP-dependent helicase rhp16, is a RAD16 homolog. It is involved in GGR via nucleotide excision repair (NER), in conjunction with rhp7, after UV irradiation. Both RAD16 and rhp16 contain a C3HC4-type RING-HC finger, as well as a DEAD-like helicase domain and a helicase superfamily C-terminal domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1907166055  17 CRLCSGYLIDATtVTECLHTFCRSCLVKYLE----ENNTCPTCRIVI 59
Cdd:cd16567     3 CGICHEEAEDPV-VARCHHVFCRACVKEYIEsapgGKVTCPTCHKPL 48

RING finger, HC subclass, found in helicase-like transcription factor (HLTF) and similar proteins; HLTF, also known as DNA-binding protein/plasminogen activator inhibitor 1 regulator, HIP116, RING finger protein 80, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 3, or sucrose nonfermenting protein 2-like 3, is a yeast RAD5 homolog found in mammals. It has both E3 ubiquitin ligase and DNA helicase activities, and plays a pivotal role in the template-switching pathway of DNA damage tolerance. It is involved in Lys-63-linked poly-ubiquitination of proliferating cell nuclear antigen (PCNA) at Lys-164 and in the regulation of DNA damage tolerance. It shows double-stranded DNA translocase activity with 3'-5' polarity, thereby facilitating regression of the replication fork. HLTF contains an N-terminal HIRAN (HIP116 and RAD5 N-terminal) domain, a SWI/SNF helicase domain that is divided into N- and C-terminal parts by an insertion of a C3HC4-type RING-HC finger involved in the poly-ubiquitination of PCNA.

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 1907166055  30 VTECLHTFCRSCLVKYLE-ENNTCPTCRIVIHQSH 63
Cdd:cd16509    18 ITPCAHVFCRRCICEVIQrEKAKCPMCRAPLSASD 52

RING finger, HC subclass, found in tripartite motif-containing proteins TRIM13, TRIM59 and similar proteins; TRIM13 and TRIM59, two closely related tripartite motif-containing proteins, belong to the C-V subclass of the TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domain, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, followed by a C-terminal transmembrane domain. TRIM13, also known as B-cell chronic lymphocytic leukemia tumor suppressor Leu5, leukemia-associated protein 5, putative tumor suppressor RFP2, RING finger protein 77 (RNF77), or Ret finger protein 2, is an endoplasmic reticulum (ER) membrane anchored E3 ubiquitin-protein ligase that interacts with proteins localized to the ER, including valosin-containing protein (VCP), a protein indispensable for ER-associated degradation (ERAD). TRIM59, also known as RING finger protein 104 (RNF104) or tumor suppressor TSBF-1, is a putative E3 ubiquitin-protein ligase that functions as a novel multiple cancer biomarker for immunohistochemical detection of early tumorigenesis.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1907166055  15 ITCRLCsGYLIDATTVTECLHTFCRSCLVKYLEENNT-------CPTCR 56
Cdd:cd16581     3 LTCSIC-YNIFDDPKILPCSHTFCKNCLEKLLAASGYyllaslkCPTCR 50

RING finger, HC subclass, found in Equid alphaherpesvirus 1 (Equine herpesvirus 1/EHV-1) regulatory protein and similar proteins; EHV-1 regulatory protein belongs to the Vmw110 (IPC0) protein family. It contains a typical C3HC4-type RING-HC finger and binds zinc stably.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1907166055  17 CRLCSGYLIDATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIH 60
Cdd:cd23130     3 CPICLDDPEDEAITLPCLHQFCYTCILRWLQTSPTCPLCKTPVT 46

RING finger, HC subclass, found in tripartite motif-containing protein 72 (TRIM72) and similar proteins; TRIM72, also known as Mitsugumin-53 (MG53), is a muscle-specific protein that plays a central role in cell membrane repair by nucleating the assembly of the repair machinery at muscle injury sites. It is required in repair of alveolar epithelial cells under plasma membrane stress failure. It interacts with dysferlin to regulate sarcolemmal repair. Upregulation of TRIM72 develops obesity, systemic insulin resistance, dyslipidemia, and hyperglycemia, as well as induces diabetic cardiomyopathy through transcriptional activation of the peroxisome proliferation-activated receptor alpha (PPAR-alpha) signaling pathway. Compensation for the absence of AKT signaling by ERK signaling during TRIM72 overexpression leads to pathological hypertrophy. Moreover, TRIM72 functions as a novel negative feedback regulator of myogenesis by targeting insulin receptor substrate-1 (IRS-1). It is transcriptionally activated by the synergism of myogenin (MyoD) and myocyte enhancer factor 2 (MEF2). TRIM72 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1907166055  15 ITCRLCSGyLIDATTVTECLHTFCRSCLVKYLEENNT----CPTCR 56
Cdd:cd16612     5 LSCPLCLK-LFQSPVTTECGHTFCQDCLSRVPKEEDGgstsCPTCQ 49

RING finger, HC subclass, found in RING finger protein 213 (RNF213) and similar proteins; RNF213, also known as ALK lymphoma oligomerization partner on chromosome 17 or Moyamoya steno-occlusive disease-associated AAA+ and RING finger protein (mysterin), is an intracellular soluble protein that functions as an E3 ubiquitin-protein ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell. It plays a unique role in endothelial cells for proper gene expression in response to inflammatory signals from the environment. Mutations in RNF213 may be associated with Moyamoya disease (MMD), an idiopathic cerebrovascular occlusive disorder prevalent in East Asia. It also acts as a nuclear marker for acanthomorph phylogeny. RNF213 contains two tandem enzymatically active AAA+ ATPase modules and a C3HC4-type RING-HC finger. It can form a huge ring-shaped oligomeric complex.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1907166055  17 CRLCSGYLIDATTVtECLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd16561     5 CSICLEDLNDPVKL-PCDHVFCEECIRQWLPGQMSCPLCR 43

RING finger, HC subclass, found in Mus musculus tripartite motif-containing protein 43 (TRIM43) and similar propteins; This subfamily includes TRIM43A, TRIM43B and TRIM43C, which are expressed specifically in mouse preimplantation embryos. They contain a typical C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1907166055  15 ITCRLCSGYLIDATTVtECLHTFCRSCLVKYLEE---NNTCPTCRIVIHQ 61
Cdd:cd23133     4 LTCSICQGIFMNPVYL-RCGHKFCEACLLLFQEDikfPAYCPMCRQPFNQ 52

RING finger, H2 subclass, found in RING finger protein 24 (RNF24) and similar proteins; RNF24 is an intrinsic membrane protein localized in the Golgi apparatus. It specifically interacts with the ankyrin-repeats domains (ARDs) of TRPC1, -3, -4, -5, -6, and -7, and affects TRPC intracellular trafficking without affecting their activity. RNF24 contains an N-terminal transmembrane domain and a C-terminal C3H2C3-type RING-H2 finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1907166055  26 DATTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSHPLQ 66
Cdd:cd16675    14 DELGICPCKHAFHRKCLIKWLEVRKVCPLCNMPVLQLAQLH 54

RING finger, HC subclass, found in tripartite motif-containing protein 26 (TRIM26) and similar proteins; TRIM26, also known as acid finger protein (AFP), RING finger protein 95 (RNF95), or zinc finger protein 173 (ZNF173), is an E3 ubiquitin-protein ligase that negatively regulates interferon-beta production and antiviral response through polyubiquitination and degradation of nuclear transcription factor IRF3. It functions as an important regulator for RNA virus-triggered innate immune response by bridging TBK1 to NEMO (NF-kappaB essential modulator, also known as IKKgamma) and mediating TBK1 activation. It also acts as a novel tumor suppressor of hepatocellular carcinoma by regulating cancer cell proliferation, colony forming ability, migration, and invasion. TRIM26 belongs the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, a B-box, and two coiled coil domains, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1907166055  15 ITCRLCSGYLIDATTVtECLHTFCRSCLVKYLE-----ENNTCPTCR 56
Cdd:cd16598     5 VTCSICLDYLRDPVTI-DCGHNFCRSCITDYCPisgghERPVCPLCR 50

RING finger, H2 subclass, found in RING finger proteins RNF126, RNF115, and similar proteins; This subfamily includes RING finger proteins RNF126, RNF115, and similar proteins. RNF126 is a Bag6-dependent E3 ubiquitin ligase that is involved in the mislocalized protein (MLP) pathway of quality control. It regulates the retrograde sorting of the cation-independent mannose 6-phosphate receptor (CI-MPR). RNF126 promotes cancer cell proliferation by targeting the tumor suppressor p21 for ubiquitin-mediated degradation, and could be a novel therapeutic target in breast and prostate cancers. It is also able to ubiquitylate cytidine deaminase (AID), a poorly soluble protein that is essential for antibody diversification. RNF115, also known as Rab7-interacting ring finger protein (Rabring 7), or zinc finger protein 364 (ZNF364), or breast cancer-associated gene 2 (BCA2), is an E3 ubiquitin-protein ligase that is an endogenous inhibitor of adenosine monophosphate-activated protein kinase (AMPK) activation; this inhibition increases the efficacy of metformin in breast cancer cells. It also functions as a cofactor in the restriction imposed by tetherin on HIV-1, and targets HIV-1 Gag for lysosomal degradation, impairing virus assembly and release, in a tetherin-independent manner. Moreover, RNF115 is a Rab7-binding protein that stimulates c-Myc degradation through mono-ubiquitination of MM-1. It also plays crucial roles as a Rab7 target protein in vesicle traffic to late endosome/lysosome and lysosome biogenesis. RNF115 and RNF126 associate with the epidermal growth factor receptor (EGFR) and promote ubiquitylation of EGFR, suggesting they play a role in the ubiquitin-dependent sorting and downregulation of membrane receptors. Both of them contain an N-terminal BCA2 Zinc-finger domain (BZF), AKT-phosphorylation sites, and a C-terminal C3H2C3-type RING-H2 finger.

                          10        20
                  ....*....|....*....|....
gi 1907166055  33 CLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd16667    20 CKHLFHPDCIVPWLELHNSCPVCR 43

Modified RING finger, HC subclass (C3HC3D-type), found in ligand of Numb protein LNX1, LNX2, and similar proteins; The ligand of Numb protein X (LNX) family, also known as PDZ and RING (PDZRN) family, includes LNX1-5, which can interact with Numb, a key regulator of neurogenesis and neuronal differentiation. LNX5 (also known as PDZK4 or PDZRN4L) shows high sequence homology to LNX3 and LNX4, but it lacks the RING domain. LNX1-4 proteins function as E3 ubiquitin ligases and have a unique domain architecture consisting of an N-terminal RING-HC finger for E3 ubiquitin ligase activity and either two or four PDZ domains necessary for substrate-binding. LNX1/LNX2-like proteins contain a modified C3HC3D-type RING-HC finger and four PDZ domains. This model corresponds to the RING finger.

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 1907166055  16 TCRLCSGYLIDATTvTECLHTFCRSCLVKYLEENNTCP 53
Cdd:cd16637     3 TCHICLQPLVEPLD-TPCGHTFCYKCLTNYLKIQQCCP 39

RING finger, HC subclass, found in Dictyostelium discoideum Ras guanine nucleotide exchange factor O (RasGEFO) and similar proteins; RasGEFO, also known as RasGEF domain-containing protein O, functions as a Ras guanine-nucleotide exchange factor (RasGEFs), activating Ras by catalyzing the replacement of GDP with GTP. RasGEFs are particularly important for signaling in development and chemotaxis in many organisms, including Dictyostelium. RasGEFO contains a C3HC4-type RING-HC finger that may be responsible for E3 ubiquitin ligase activity.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1907166055  12 NAHITCRLCSGYLIDATTVTECLHTFCRSCLVKYLeENNTCPTCRIVIHQS 62
Cdd:cd16507     7 LQSLTCGICQNLFKDPNTLIPCGHAFCLDCLTTNA-SIKNCIQCKVEYTTY 56

RING finger, HC subclass, found in tripartite motif-containing proteins TRIM43, TRIM48, TRIM49, TRIM51, TRIM64 and similar proteins; The family includes a group of closely related uncharacterized tripartite motif-containing proteins, TRIM43, TRIM43B, TRIM48/RNF101, TRIM49/RNF18, TRIM49B, TRIM49C/TRIM49L2, TRIM49D/TRIM49L, TRIM51/SPRYD5, TRIM64, TRIM64B, and TRIM64C, whose biological function remain unclear. TRIM49, also known as testis-specific RING-finger protein, has moderate similarity with SS-A/Ro52 antigen, suggesting it may be one of the target proteins of autoantibodies in the sera of patients with these autoimmune disorders. All family members belong to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. In RBCC region, they all have a C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1907166055  15 ITCRLCSGYLIDATTVtECLHTFCRSCLVKYLEENNT---CPTCRIVIHQ 61
Cdd:cd16603     5 LTCPICMNYFIDPVTI-DCGHSFCRPCLYLNWQDIPFlaqCPECRKTTEQ 53

RING finger, HC subclass, found in peroxin-10 (PEX10) and similar proteins; PEX10, also known as peroxisome biogenesis factor 10, peroxisomal biogenesis factor 10, peroxisome assembly protein 10, or RING finger protein 69 (RNF69), is an integral peroxisomal membrane protein with two transmembrane regions and a C3HC4-type RING-HC finger within its cytoplasmically exposed C-terminus. It plays an essential role in peroxisome assembly, import of target substrates, and recycling or degradation of protein complexes and amino acids. It is an essential component of the spinal locomotor circuit, and thus its mutations may be involved in peroxisomal biogenesis disorders (PBD). Mutations in human PEX10 also result in autosomal recessive ataxia. Moreover, PEX10 functions as an E3-ubiquitin ligase with an E2, UBCH5C. It mono- or poly-ubiquitinates PEX5, a key player in peroxisomal matrix protein import, in a UBC4-dependent manner, to control PEX5 receptor recycling or degradation. It also links the E2 ubiquitin conjugating enzyme PEX4 to the protein import machinery of the peroxisome.

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1907166055  28 TTVTECLHTFCRSCLVKYLEENNTCPTCRIVIHQSH 63
Cdd:cd16527    13 PTATPCGHLFCWSCITEWCNEKPECPLCREPFQPQR 48

first RING finger, HC subclass, found in Arabidopsis thaliana ORTHRUS and similar proteins; This subfamily includes Arabidopsis thaliana ORTHRUS 1-5. They are E3 ubiquitin-protein ligases that may participate in CpG methylation-dependent transcriptional regulation and/or epigenetic transcriptional silencing. ORTHRUS 1 mediates ubiquitination with the E2 ubiquitin-conjugating enzymes UBC11, UBC8 and UBC8 homologs (e.g. UBC10, UBC11, UBC28 and UBC29) but not with UBC27, UBC30, UBC32, UBC34 and UBC36. ORTHRUS 2 and 5 mediate ubiquitination with the E2 ubiquitin-conjugating enzyme UBC11. ORTHRUS 1 and 2 promote methylation-mediated gene silencing leading, for example, to early flowering. They can bind to CpG, CpNpG, and CpNpN DNA motifs, with a strong preference for methylated forms, and with highest affinity for CpG substrates. Members of this subfamily contain two typical C3HC4-type RING-HC fingers. This model corresponds to the first one.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1907166055  14 HITCRLCSGyLIDATTVTECLHTFCRSCLVKYLEENN-TCPTCRIVIH 60
Cdd:cd23138     2 ELNCSFCMQ-LPERPVTTPCGHNFCLKCFQKWMGQGKkTCGTCRSPIP 48

RING finger, HC subclass, found in Saccharomyces cerevisiae radiation sensitivity protein 18 (RAD18) and similar proteins; RAD18, also called RING-type E3 ubiquitin transferase RAD18, acts as a postreplication repair E3 ubiquitin-protein ligase that associates with the E2 ubiquitin conjugating enzyme UBC2/RAD6 to form the UBC2-RAD18 ubiquitin ligase complex involved in postreplicative repair (PRR) of damaged DNA. The UBC2-RAD18 complex cooperates with RAD5 and the UBC13-MMS2 dimer to attach mono-ubiquitin chains on 'Lys-164' of POL30, which is necessary for PRR. The UBC2-RAD18 complex is also involved in prevention of spontaneous mutations caused by 7,8-dihydro-8-oxoguanine. RAD18 is an E3 RING-finger protein belonging to the UBC2/RAD6 epistasis group. It contains a typical C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1907166055  15 ITCRLCSGYLiDATTVTECLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd23148     4 LRCHICKDLL-KAPMRTPCNHTFCSFCIRTHLNNDARCPLCK 44

RING finger- and WD40-associated ubiquitin-like (RAWUL) domain found in polycomb group RING finger protein 2 (PCGF2); PCGF2, also termed DNA-binding protein Mel-18, or RING finger protein 110 (RNF110), or zinc finger protein 144 (ZNF144), is one of six PcG RING finger (PCGF) homologs (PCGF1/NSPc1, PCGF2/Mel-18, PCGF3, PCGF4/BMI1, PCGF5, and PCGF6/MBLR) and serves as the core component of a canonical polycomb repressive complex 1 (PRC1), which is composed of a chromodomain-containing protein (CBX2, CBX4, CBX6, CBX7 or CBX8) and a polyhomeotic protein (PHC1, PHC2, or PHC3). Like other PCGF homologs, PCGF2 associates with ring finger protein 2 (RNF2) to form a RNF2-PCGF heterodimer, which is catalytically competent as an E3 ubiquitin transferase and is the scaffold for the assembly of additional components. Moreover, PCGF2 uniquely regulates PRC1 to specify mesoderm cell fate in embryonic stem cells. It is required for PRC1 stability and maintenance of gene repression in embryonic stem cells (ESCs) and essential for ESC differentiation into early cardiac-mesoderm precursors. PCGF2 also plays a significant role in the angiogenic function of endothelial cells (ECs) by regulating endothelial gene expression. Furthermore, PCGF2 is a SUMO-dependent regulator of hormone receptors. It facilitates the deSUMOylation process by inhibiting PCGF4/BMI1-mediated ubiquitin-proteasomal degradation of SUMO1/sentrin-specific protease 1 (SENP1). It is also a novel negative regulator of breast cancer stem cells (CSCs) that inhibits the stem cell population, and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling. PCGF2 contains a C3HC4-type RING-HC finger, and a RAWUL domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1907166055 151 DEQVSICLECNSSKLRGLKRkWIRCSAQATVLHLKKFIAKKLNLSSFNELDILCNEEILGKDHTL 215
Cdd:cd17164    16 KKQRPASPGDPFKEQRNGKR-FLRCPAAMTVMHLAKFLRNKMDVPSKYRVEVLYEDEPLKDYYTL 79

RING finger, HC subclass, found in recombination activating gene-1 (RAG-1) and similar proteins; RAG-1, also known as V(D)J recombination-activating protein 1, RING finger protein 74 (RNF74), or endonuclease RAG1, is the catalytic component of the RAG complex, a multiprotein complex that mediates the DNA cleavage phase during V(D)J recombination. RAG1 is a lymphoid-specific factor that mediates DNA-binding to conserved recombination signal sequences (RSS) and catalyzes DNA cleavage activities by introducing a double-strand break between the RSS and the adjacent coding segment. It also functions as an E3 ubiquitin-protein ligase that mediates monoubiquitination of histone H3, which is required for the joining step of V(D)J recombination. RAG-1 contains an N-terminal C3HC4-type RING-HC finger that mediates monoubiquitylation of histone H3, an adjacent C2H2-type zinc finger, and a nonamer binding (NBD) DNA-binding domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1907166055  15 ITCRLCSGYLIDATTvTECLHTFCRSCLVKYLEE-NNTCPTCR 56
Cdd:cd16530     3 VSCQVCEHILADPVQ-TPCKHLFCRTCILKCLKVmGSYCPSCR 44

RING finger, HC subclass, found in Saccharomyces cerevisiae increased recombination centers protein 20 (IRC20) and similar proteins; IRC20 is an uncharacterized ATP-dependent helicase that is probably involved in a pathway contributing to genomic integrity. IRC20 contains a typical C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1907166055  12 NAHITCRLCSGYlIDATTVTECLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd23135     1 KQKLSCSICFSE-IRSGAILKCGHFFCLSCIASWLREKSTCPLCK 44

RING finger, HC subclass, found in topoisomerase I-binding arginine/serine-rich protein (Topors) and similar proteins; Topors, also known as topoisomerase I-binding RING finger protein, tumor suppressor p53- binding protein 3, or p53-binding protein 3 (p53BP3), is a ubiquitously expressed nuclear E3 ubiquitin-protein ligase that can ligate both ubiquitin and small ubiquitin-like modifier (SUMO) to substrate proteins in the nucleus. It contains an N-terminal C3HC4-type RING-HC finger which ligates ubiquitin to its target proteins including DNA topoisomerase I, p53, NKX3.1, H2AX, and the AAV-2 Rep78/68 proteins. As a RING-dependent E3 ubiquitin ligase, Topors works with the E2 enzymes UbcH5a, UbcH5c, and UbcH6, but not with UbcH7, CDC34, or UbcH2b. Topors acts as a tumor suppressor in various malignancies. It regulates p53 modification, suggesting it may be responsible for astrocyte elevated gene-1 (AEG-1, also known as metadherin, or LYRIC) ubiquitin modification. Plk1-mediated phosphorylation of Topors inhibits Topors-mediated sumoylation of p53, whereas p53 ubiquitination is enhanced, leading to p53 degradation. It also functions as a negative regulator of the prostate tumor suppressor NKX3.1. Moreover, Topors is associated with promyelocytic leukemia nuclear bodies, and may be involved in the cellular response to camptothecin. It also plays a key role in the turnover of H2AX protein, discriminating the type of DNA damaging stress. Furthermore, Topors is a cilia-centrosomal protein associated with autosomal dominant retinal degeneration. Mutations in TOPORS cause autosomal dominant retinitis pigmentosa (adRP).

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1907166055  16 TCRLCSGYLIDATTVTE-CLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd16574     3 SCPICLDRFENEKAFLDgCFHAFCFTCILEWSKVKNECPLCK 44

RING finger, H2 subclass, found in RING finger protein 126 (RNF126) and similar proteins; RNF126 is a Bag6-dependent E3 ubiquitin ligase that is involved in the mislocalized protein (MLP) pathway of quality control. It regulates the retrograde sorting of the cation-independent mannose 6-phosphate receptor (CI-MPR). Moreover, RNF126 promotes cancer cell proliferation by targeting the tumor suppressor p21 for ubiquitin-mediated degradation, and could be a novel therapeutic target in breast and prostate cancers. It is also able to ubiquitylate cytidine deaminase (AID), a poorly soluble protein that is essential for antibody diversification. In addition, RNF126 and the related protein, RNF115 associate with the epidermal growth factor receptor (EGFR) and promote ubiquitylation of EGFR, suggesting they play a role in the ubiquitin-dependent sorting and downregulation of membrane receptors. RNF126 contains an N-terminal BCA2 Zinc-finger domain (BZF), the AKT-phosphorylation sites, and the C-terminal C3H2C3-type RING-H2 finger.

                          10        20
                  ....*....|....*....|....
gi 1907166055  33 CLHTFCRSCLVKYLEENNTCPTCR 56
Cdd:cd16801    20 CNHLFHNDCIVPWLEQHDTCPVCR 43

RING finger, HC subclass, found in RING finger protein 168 (RNF168) and similar proteins; RNF168 is an E3 ubiquitin-protein ligase that promotes noncanonical K27 ubiquitination to signal DNA damage. It, together with RNF8, functions as a DNA damage response (DDR) factor that promotes a series of ubiquitylation events on substrates, such as H2A and H2AX with H2AK13/15 ubiquitylation, facilitates recruitment of repair factors p53-binding protein 1 (53BP1) or the RAP80-BRCA1 complex to sites of double-strand breaks (DSBs), and inhibits homologous recombination (HR) in cells deficient in the tumor suppressor BRCA1. RNF168 also promotes H2A neddylation, which antagonizes ubiquitylation of H2A and regulates DNA damage repair. Moreover, RNF168 forms a functional complex with RAD6A or RAD6B during the DNA damage response. RNF168 contains an N-terminal C3HC4-type RING-HC finger that catalyzes H2A-K15ub and interacts with H2A, and two MIU (motif interacting with ubiquitin) domains responsible for the interaction with K63 linked poly-ubiquitin.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1907166055  16 TCRLCSGYLIDATTVTeCLHTFCRSCLVKYLEENN-TCPTCRIVI 59
Cdd:cd16550     2 LCPICLEILVEPVTLP-CNHTLCMPCFQSTVEKASlCCPLCRLRI 45

RING finger, HC subclass, found in tripartite motif-containing protein TRIM17 and similar proteins; TRIM17, also known as RING finger protein 16 (RNF16) or testis RING finger protein (Terf), is a crucial E3 ubiquitin ligase that is necessary and sufficient for neuronal apoptosis and contributes to Mcl-1 ubiquitination in cerebellar granule neurons (CGNs). It interacts in a SUMO-dependent manner with nuclear factor of activated T cell NFATc3 transcription factor, and thus inhibits the activity of NFATc3 by preventing its nuclear localization. In contrast, it binds to and inhibits NFATc4 transcription factor in a SUMO-independent manner. Moreover, TRIM17 stimulates degradation of kinetochore protein ZW10 interacting protein (ZWINT), a known component of the kinetochore complex required for the mitotic spindle checkpoint, and negatively regulates cell proliferation. TRIM17 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1907166055  16 TCRLCSGYLIDATTvTECLHTFCRSCLVKYLEE------------NNTCPTCRIVIHQ 61
Cdd:cd16595     7 TCSICLDYFTDPVM-TTCGHNFCRACIQLSWEKargkkgrrkqkgSFPCPECREMSPQ 63

RING finger, HC subclass, found in ligand of Numb protein LNX3, LNX4, and similar proteins; The ligand of Numb protein X (LNX) family, also known as PDZ and RING (PDZRN) family, includes LNX1-5, which can interact with Numb, a key regulator of neurogenesis and neuronal differentiation. LNX5 (also known as PDZK4, or PDZRN4L) shows high sequence homology to LNX3 and LNX4, but it lacks the RING domain. LNX1-4 proteins function as E3 ubiquitin ligases and have a unique domain architecture consisting of an N-terminal RING-HC finger for E3 ubiquitin ligase activity and either two or four PDZ domains necessary for the substrate-binding. This family corresponds to LNX3/LNX4-like proteins, which contains a C3HC4-type RING-HC finger and two PDZ domains.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1907166055  17 CRLCSGYLIDATTvTECLHTFCRSCLVKYLEENNTCP-TCR 56
Cdd:cd16512     3 CKLCLGVLEEPLA-TPCGHVFCAGCVLPWVVRNGSCPlKCE 42

RING finger, HC subclass, found in tripartite motif-containing protein 59 (TRIM59) and similar proteins; TRIM59, also known as RING finger protein 104 (RNF104) or tumor suppressor TSBF-1, is a putative E3 ubiquitin-protein ligase that functions as a novel multiple cancer biomarker for immunohistochemical detection of early tumorigenesis. It is upregulated in gastric cancer and promotes gastric carcinogenesis by interacting with and targeting the P53 tumor suppressor for its ubiquitination and degradation. It also acts as a novel accessory molecule involved in cytotoxicity of BCG-activated macrophages (BAM). Moreover, TRIM59 may serve as a multifunctional regulator for innate immune signaling pathways. It interacts with ECSIT and negatively regulates nuclear factor-kappaB (NF- kappa B) and interferon regulatory factor (IRF)-3/7-mediated signal pathways. TRIM59 belongs to the C-V subclass of the TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domain, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region. In addition, TRIM59 contains a C-terminal transmembrane domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1907166055  15 ITCRLCSGYLIDATtVTECLHTFCRSCLVKYLEENNT------------CPTCR 56
Cdd:cd16763     4 LTCSVCYSLFEDPR-VLPCSHTFCRNCLENILQVSGNfsiwrplrpplkCPNCR 56