RING finger, HC subclass, found in really interesting new gene 2 protein (RING2) and similar proteins; 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. RING2 is a core component 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. The enzymatic activity of RING2 is enhanced by the interaction with BMI1/PCGF4, and it is dispensable for early embryonic development and much of the gene repression activity of PRC1. Moreover, RING2 plays a key role in terminating neural precursor cell (NPC)-mediated production of subcerebral projection neurons (SCPNs) during neocortical development. It also plays a critical role in nonhomologous end-joining (NHEJ)-mediated end-to-end chromosome fusions. Furthermore, RING2 is essential for expansion of hepatic stem/progenitor cells. It promotes hepatic stem/progenitor cell expansion through simultaneous suppression of cyclin-dependent kinase inhibitors (CDKIs) Cdkn1a and Cdkn2a, known negative regulators of cell proliferation. RING2 also negatively regulates p53 expression through directly binding with both p53 and MDM2 and promoting MDM2-mediated p53 ubiquitination in selective cancer cell types to stimulate tumor development. RING2 contains a C3HC4-type RING-HC finger.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 26354897  37 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 113
Cdd:cd16740   1 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 77

RING finger, HC subclass, found in really interesting new gene 2 protein (RING2) and similar proteins; 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. RING2 is a core component 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. The enzymatic activity of RING2 is enhanced by the interaction with BMI1/PCGF4, and it is dispensable for early embryonic development and much of the gene repression activity of PRC1. Moreover, RING2 plays a key role in terminating neural precursor cell (NPC)-mediated production of subcerebral projection neurons (SCPNs) during neocortical development. It also plays a critical role in nonhomologous end-joining (NHEJ)-mediated end-to-end chromosome fusions. Furthermore, RING2 is essential for expansion of hepatic stem/progenitor cells. It promotes hepatic stem/progenitor cell expansion through simultaneous suppression of cyclin-dependent kinase inhibitors (CDKIs) Cdkn1a and Cdkn2a, known negative regulators of cell proliferation. RING2 also negatively regulates p53 expression through directly binding with both p53 and MDM2 and promoting MDM2-mediated p53 ubiquitination in selective cancer cell types to stimulate tumor development. RING2 contains a C3HC4-type RING-HC finger.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 26354897  37 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 113
Cdd:cd16740   1 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 77

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 26354897    50 MCPICLDMLKNTMTTKECLHRFCADCIITALRSGNkECPTC 90
Cdd:pfam13923   1 MCPICMDMLKDPSTTTPCGHVFCQDCILRALEASN-ECPLC 40

Uncharacterized conserved protein, contains RING Zn-finger [General function prediction only];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 26354897  11 QPLSKTWELslYELQRTPQEAITDGLEIVVSPrslHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTC 90
Cdd:COG5222 242 QPDVQSWEK--YQQRTKAVAEIPDQVYKMQPP---NISLKCPLCHCLLRNPMKTPCCGHTFCDECIGTALLDSDFKCPNC 316

                        90
                ....*....|...
gi 26354897  91 RKKLVSKRSLRPD 103
Cdd:COG5222 317 SRKDVLLDGLTPD 329

N1R/p28-like protein; Provisional

                         10        20        30
                 ....*....|....*....|....*....|....*
gi 26354897   67 CLHRFCADCIiTALRSGNKECPTCRKKLVSKRSLR 101
Cdd:PHA02929 200 CNHVFCIECI-DIWKKEKNTCPVCRTPFISVIKSR 233

RING finger- and WD40-associated ubiquitin-like (RAWUL) domain found in really interesting new gene proteins RING1, RING2 and similar proteins; RING1, also termed polycomb complex protein RING1, or RING finger protein 1 (RNF1), or RING finger protein 1A (RING1A), has been identified as a transcriptional repressor that is associated with the Polycomb group (PcG) protein complex involved in stable repression of gene activity. RING2, also termed huntingtin-interacting protein 2-interacting protein 3, or HIP2-interacting protein 3, or protein DinG, or RING finger protein 1B (RING1B), or 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 in this family contain a C3HC4-type RING-HC finger, and a RAWUL domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 26354897 225 EIELVFRPHPTLMEKDDSA-QTRYIKTSGHATVDHLSKYLAVRLALEELRSKGESNqMNLDTASEKQYTIYIATATGQFT 303
Cdd:cd17086   1 EIELVFKPHPDEEEKDLDEnQTRYIKTSANATVDHLSKYLAMRLALERQNEEGESD-GNTADESERQYTIYIATGPGQYV 79

                        90       100
                ....*....|....*....|....*..
gi 26354897 304 LLNGSFSLELVSEKYWKVNKPMELYYA 330
Cdd:cd17086  80 LLDGSMTLEQVNEKYWKVNKPLELYYA 106

RING finger, HC subclass, found in really interesting new gene 2 protein (RING2) and similar proteins; 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. RING2 is a core component 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. The enzymatic activity of RING2 is enhanced by the interaction with BMI1/PCGF4, and it is dispensable for early embryonic development and much of the gene repression activity of PRC1. Moreover, RING2 plays a key role in terminating neural precursor cell (NPC)-mediated production of subcerebral projection neurons (SCPNs) during neocortical development. It also plays a critical role in nonhomologous end-joining (NHEJ)-mediated end-to-end chromosome fusions. Furthermore, RING2 is essential for expansion of hepatic stem/progenitor cells. It promotes hepatic stem/progenitor cell expansion through simultaneous suppression of cyclin-dependent kinase inhibitors (CDKIs) Cdkn1a and Cdkn2a, known negative regulators of cell proliferation. RING2 also negatively regulates p53 expression through directly binding with both p53 and MDM2 and promoting MDM2-mediated p53 ubiquitination in selective cancer cell types to stimulate tumor development. RING2 contains a C3HC4-type RING-HC finger.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 26354897  37 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 113
Cdd:cd16740   1 EIVVSPRSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 77

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        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 26354897  48 ELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKI 113
Cdd:cd16531   1 ELMCPICLGIIKNTMTVKECLHRFCAECIEKALRLGNKECPTCRKHLPSRRSLRPDPNFDALISKI 66

RRING finger- and WD40-associated ubiquitin-like (RAWUL) domain found in PCGF1-6, RING1 and -2, DRIP and similar proteins; structurally similar to a beta-grasp ubiquitin-like fold; The family 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 that can remodel chromatin such that epigenetic silencing of genes takes place, and are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies. 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 are involved in the maintenance of gene repression and 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, and a RAWUL domain that might be responsible for interaction with Cbx members of the Polycomb repression complexes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 26354897 225 EIELVFRPHPTLME-KDDSAQTRYIKTSGHATVDHLSKYLAVRLALEelrskgesnqmnldtaSEKQYTIYIATatgqfT 303
Cdd:cd16102   1 QVSLSLEPSESNLGgKLPQLEKPYLRCSARATVGHLKKFLRRKLKLD----------------SEQDLDILCRG-----E 59

                        90       100
                ....*....|....*....|....*...
gi 26354897 304 LLNGSFSLELVSEKYWKV-NKPMELYYA 330
Cdd:cd16102  60 LLGKEHTLKFIWRTRWRKqDGPLVLQYR 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        50
                ....*....|....*....|....*....|....*....|....*....|
gi 26354897  47 SELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVS 96
Cdd:cd16620   2 DELKCPICKDLMKDAVLTPCCGNSFCDECIRTALLEEDFTCPTCKEPDVS 51

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 26354897    51 CPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTC 90
Cdd:pfam00097   1 CPICLEEPKDPVTLLPCGHLFCSKCIRSWLESGNVTCPLC 40

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 26354897  49 LMCPICLDMLKNTMTTkECLHRFCADCIITALRSGNKECPTC 90
Cdd:cd16449   1 LECPICLERLKDPVLL-PCGHVFCRECIRRLLESGSIKCPIC 41

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 26354897  48 ELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKLVS 96
Cdd:cd16503   2 NLTCSICQDLLHDCVSLQPCMHNFCAACYSDWMERSNTECPTCRATVQR 50

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 26354897  50 MCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKeCPTCR 91
Cdd:cd16506   2 TCPICLDEIQNKKTLEKCKHSFCEDCIDRALQVKPV-CPVCG 42

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        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 26354897  44 SLHSELMCPICLDMLKNTMTTkECLHRFCADCIIT--ALRSGNKECPTCRkKLVSKRSLRPDP 104
Cdd:cd16594   1 SLQEELTCPICLDYFTDPVTL-DCGHSFCRACIARcwEEPETSASCPQCR-ETCPQRNLRPNR 61

RING finger, HC subclass, found in RING finger protein 222 (RNF222) and similar proteins; RNF222 is an uncharacterized C3HC4-type RING-HC finger-containing protein. It may function as an E3 ubiquitin-protein ligase.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 26354897  51 CPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCRKKL 94
Cdd:cd16564   3 CPVCYEDFDDAPRILSCGHSFCEDCLVKQLVSMTISCPICRRVT 46

RING finger, HC subclass, found in tripartite motif-containing protein TRIM21 and similar proteins; TRIM21, also known as 52 kDa Ro protein, 52 kDa ribonucleoprotein autoantigen Ro/SS-A, Ro(SS-A), RING finger protein 81 (RNF81), or Sjoegren syndrome type A antigen (SS-A), is a ubiquitously expressed E3 ubiquitin-protein ligase and a high affinity antibody receptor uniquely expressed in the cytosol of mammalian cells. As a cytosolic Fc receptor, TRIM21 binds the Fc of virus-associated antibodies and targets the complex in the cytosol for proteasomal degradation in a process known as antibody-dependent intracellular neutralization (ADIN), and provides an intracellular immune response to protect host defense against pathogen infection. It shows remarkably broad isotype specificity as it does not only bind IgG, but also IgM and IgA. Moreover, TRIM21 promotes the cytosolic DNA sensor cGAS and the cytosolic RNA sensor RIG-I sensing of viral genomes during infection by antibody-opsonized virus. It stimulates inflammatory signaling and activates innate transcription factors, such as nuclear factor-kappaB (NF-kappaB). TRIM21 also plays an essential role in p62-regulated redox homeostasis, suggesting it may be a viable target for treating pathological conditions resulting from oxidative damage. Furthermore, TRIM21 may have implications for various autoimmune diseases associated with uncontrolled antiviral signaling through the regulation of Nmi-IFI35 complex-mediated inhibition of innate antiviral response. TRIM21 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 26354897  48 ELMCPICLDMLKNTMTTkECLHRFCADCIITALRSGNKECPTCRKKLVsKRSLRPD 103
Cdd:cd16596   9 EVTCPICLDPFVEPVSI-ECGHSFCQECISQVGKGGGSVCPVCRQRFL-LKNLRPN 62

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 26354897  48 ELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKeCPTCR 91
Cdd:cd16711   1 EETCPICLGEIQNKKTLDKCKHSFCEDCITRALQVKKA-CPMCG 43

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 26354897  50 MCPICLDMLKNTMT-TKECLHRFCADCIitaLR-SGNK-ECPTCRKK 93
Cdd:cd16574   3 SCPICLDRFENEKAfLDGCFHAFCFTCI---LEwSKVKnECPLCKQP 46

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        40
                ....*....|....*....|....*....|....*....|.
gi 26354897  51 CPICLDMLKNTMTTKeCLHRFCADCIITALRSGNKECPTCR 91
Cdd:cd16509   6 CAICLDSLTNPVITP-CAHVFCRRCICEVIQREKAKCPMCR 45

RING finger, HC subclass, found in tripartite motif-containing protein 77 (TRIM77) and similar proteins; TRIM77 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 two consecutive zinc-binding domains, a C3HC4-type RING-HC finger and Bbox2, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 26354897  47 SELMCPICLDMLKNTMTTKeCLHRFCADCIITAL--RSGNKECPTCRKK 93
Cdd:cd16543   2 DQLTCSICLDLLKDPVTIP-CGHSFCMNCITLLWdrKQGVPSCPQCRES 49

RING finger found in polycomb group RING finger protein 5 (PCGF5) and similar proteins; PCGF5, also known as 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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 26354897  43 RSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNkECPTCRK---KLVSKRSLRPDPNFDALISKIYPSRDE 119
Cdd:cd16737   5 RDFNPYITCRICKGYLIKPTTVTECLHTFCKSCIVQHFEDSN-DCPECGIqvhETNPLEMLRLDNTLEEIIFKLVPGLRE 83

                ....*..
gi 26354897 120 YEAHQER 126
Cdd:cd16737  84 RELQREA 90

RING finger, HC subclass, found in Saccharomyces cerevisiae POB3/SPT16 histone-associated protein 1 (ScPSH1) and similar proteins; ScPSH1 is a Cse4-specific E3 ubiquitin ligase that interacts with the kinetochore protein Pat1 and targets the degradation of budding yeast centromeric histone H3 variant, CENP-ACse4, which is essential for faithful chromosome segregation. ScPSH1 contains a C3HC4-type RING-HC finger and a DNA directed RNA polymerase domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 26354897  51 CPICLDMLKNTMTTkECLHRFCADCIITALRSG-NKECPTCRKKLVS 96
Cdd:cd16568   7 CIICHEYLYEPMVT-TCGHTYCYTCLNTWFKSNrSLSCPDCRTKITT 52

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        50
                ....*....|....*....|....*....|....*....|....*....|
gi 26354897  45 LHSELMCPICLDMLKNTMTTkECLHRFCADCIITALR---SGNKECPTCR 91
Cdd:cd16612   1 MHQDLSCPLCLKLFQSPVTT-ECGHTFCQDCLSRVPKeedGGSTSCPTCQ 49

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 26354897  45 LHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSgNKECPTCRKKLVSKR---SLRPDPNFDALISK 112
Cdd:cd16734  11 LNPHLMCALCGGYFIDAATIVECLHSFCKTCIVRYLET-NKYCPMCDVQVHKTRpllSIRSDKTLQDIVYK 80

RING finger, HC subclass, found in RING finger protein 8 (RNF8) and similar proteins; RNF8 is a telomere-associated E3 ubiquitin-protein ligase that plays an important role in DNA double-strand break (DSB) repair via histone ubiquitination. It is localized in the nucleus and interacts with class III E2s (UBE2E2, UbcH6, and UBE2E3), but not with other E2s (UbcH5, UbcH7, UbcH10, hCdc34, and hBendless). It recruits UBC13 for lysine 63-based self polyubiquitylation. Its deficiency causes neuronal pathology and cognitive decline, and its loss results in neuron degeneration. RNF8, together with RNF168, catalyzes a series of ubiquitylation events on substrates such as H2A and H2AX, with the H2AK13/15 ubiquitylation being particularly important for recruitment of repair factors p53-binding protein 1 (53BP1) or the RAP80-BRCA1 complex to sites of DSBs. RNF8 mediates the ubiquitination of gammaH2AX, and recruits 53BP1 and BRCA1 to DNA damage sites which promotes DNA damage response (DDR) and inhibits chromosomal instability. Moreover, RNF8 interacts with retinoid X receptor alpha (RXR alpha) and enhances its transcription-stimulating activity. It also regulates the rate of exit from mitosis and cytokinesis. RNF8 contains an N-terminal forkhead-associated (FHA) domain and a C-terminal C3HC4-type RING-HC finger.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 26354897  48 ELMCPICLDMLKNTmTTKECLHRFCADCIiTALRSGNKECPTCRKKLVSK-RSLRPDPNFDALISK 112
Cdd:cd16535   1 ELQCSICSELFIEA-VTLNCSHSFCSYCI-TEWMKRKKECPICRKPITSKtRSLVLDNCIDKMVEN 64

RING finger, HC subclass, found in tripartite motif-containing protein 40 (TRIM40) and similar proteins; TRIM40, also known as probable E3 NEDD8-protein ligase or RING finger protein 35 (RNF35), is highly expressed in the gastrointestinal tract including the stomach, small intestine, and large intestine. It enhances neddylation of inhibitor of nuclear factor kappaB kinase subunit gamma (IKKgamma), inhibits the activity of nuclear factor-kappaB (NF-kappaB)-mediated transcription, and thus prevents inflammation-associated carcinogenesis in the gastrointestinal tract. TRIM40 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, as well as an uncharacterized region positioned C-terminal to the RBCC domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 26354897  50 MCPICLDMLKNTMTTkECLHRFCADCII----TALRSGNKECPTCRK 92
Cdd:cd16583   7 VCPICQEPLKEAVST-DCGHLFCRMCLTqhakKASASGVFSCPVCRK 52

Modified RING finger, C3HGC3-type, found in RING finger and WD repeat domain-containing protein 3 (RFWD3) and similar proteins; RFWD3, also known as RING finger protein 201 (RNF201) or FLJ10520, is an E3 ubiquitin-protein ligase that forms a complex with Mdm2 and p53 to synergistically ubiquitinate p53 and acts as a positive regulator of p53 stability in response to DNA damage. It is phosphorylated by checkpoint kinase ATM/ATR and the phosphorylation mutant fails to stimulate p53 ubiquitination. RFWD3 also functions as a novel replication protein A (RPA)-associated protein involved in DNA replication checkpoint control. RFWD3 contains an N-terminal SQ-rich region followed by a RING finger domain that exhibits robust E3 ubiquitin ligase activity toward p53, a coiled-coil domain and three WD40 repeats in the C-terminus, the latter two of which may be responsible for protein-protein interaction. The RING finger in this family is a modified C3HGC3-type RING finger, but not a canonical C3H2C3-type RING-H2 finger or C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 26354897  51 CPICLDMLKNT----MTTKECLHRFCADCIITALRSGNKECPTCRKKlVSKRSLRP 102
Cdd:cd16450   5 CPICFEPWTSSgehrLVSLKCGHLFGYSCIEKWLKGKGKKCPQCNKK-AKRSDIRP 59

RING finger, HC subclass, found in tripartite motif-containing proteins TRIM41, TRIM52 and similar proteins; TRIM41 and TRIM52, two closely related tripartite motif-containing proteins, have dramatically expanded RING domains compared with the rest of the TRIM family proteins. TRIM41 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. In contrast, TRIM52 lacks the putative viral recognition SPRY/B30.2 domain, and thus has been classified to the C-V subclass of the TRIM family that contains only RBCC domains. TRIM41, also known as RING finger-interacting protein with C kinase (RINCK), is an E3 ubiquitin-protein ligase that promotes the ubiquitination of protein kinase C (PKC) isozymes in cells. It specifically recognizes the C1 domain of PKC isozymes. It controls the amplitude of PKC signaling by controlling the amount of PKC in the cell. TRIM52, also known as RING finger protein 102 (RNF102), is encoded by a novel, noncanonical antiviral TRIM52 gene in primate genomes with unique specificity determined by the rapidly evolving RING domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 26354897  48 ELMCPICLDMLKNTMTTkECLHRFCADCiITALRSGNkeCPTCRKKLvSKRSLRPD 103
Cdd:cd16602   3 EAVCAICLDYFKDPVSI-GCGHNFCRVC-VTQLWGFT--CPQCRKSF-PRRSFRPN 53

RING finger, HC subclass, found in RING finger protein 166 (RNF166) and similar proteins; RNF166 is encoded by the gene RNF166 targeted by thyroid hormone receptor alpha1 (TRalpha1), which is important in brain development. It plays an important role in RNA virus-induced interferon-beta production by enhancing the ubiquitination of TRAF3 and TRAF6. RNF166, together with three closely related proteins: RNF114, RNF125 and RNF138, forms a novel family of ubiquitin ligases with a C3HC4-type RING-HC finger, a C2HC-, and two C2H2-type zinc fingers, as well as a ubiquitin interacting motif (UIM).

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 26354897  48 ELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKECPTCR 91
Cdd:cd16549   1 QFSCPICLEVYHKPVVITSCGHTFCGECLQPCLQVASPLCPLCR 44

RING-type zinc-finger; This zinc-finger is a typical RING-type of plant ubiquitin ligases.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 26354897    51 CPICLDMLKNTMTTkeCLHRFCADCIITALRSGNKE--CP 88
Cdd:pfam13445   1 CPICLELFTDPVLP--CGHTFCRECLEEMSQKKGGKfkCP 38

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        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 26354897  44 SLHSELMCPICLDMLKNTMTTkECLHRFCADCIITA-----------LRSGNKECPTCRkKLVSKRSLRPD 103
Cdd:cd16595   1 RLQEEATCSICLDYFTDPVMT-TCGHNFCRACIQLSwekargkkgrrKQKGSFPCPECR-EMSPQRNLRPN 69

RING finger, HC subclass, found in tripartite motif-containing protein 56 (TRIM56) and similar proteins; TRIM56, also known as RING finger protein 109 (RNF109), is a virus-inducible E3 ubiquitin ligase that restricts pestivirus infection. It positively regulates the Toll-like receptor 3 (TLR3) antiviral signaling pathway, and possesses antiviral activity against bovine viral diarrhea virus (BVDV), a ruminant pestivirus classified within the family Flaviviridae shared by tick-borne encephalitis virus (TBEV). It also possesses antiviral activity against two classical flaviviruses, yellow fever virus (YFV) and dengue virus (DENV), as well as a human coronavirus, HCoV-OC43, which is responsible for a significant share of common cold cases. It may not act on positive-strand RNA viruses indiscriminately. Moreover, TRIM56 is an interferon-inducible E3 ubiquitin ligase that modulates STING to confer double-stranded DNA-mediated innate immune responses. TRIM56 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, as well as an uncharacterized region positioned C-terminal to the RBCC domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 26354897  49 LMCPICLDMLKnTMTTKECLHRFCADCIITALRSGNKECPTCRKKL 94
Cdd:cd16584   2 LACKICLEQLR-APKTLPCLHTYCQDCLAQLADGGRVRCPECRETV 46

RING finger, HC subclass, found in Arabidopsis thaliana protein BREAST CANCER SUSCEPTIBILITY 1 homolog (AtBRCA1) and similar proteins; AtBRCA1 plays a role in DNA repair and in cell-cycle control. It is required for the repair of DNA double-strand breaks (DSBs), both natural and induced by genotoxic stress, by homologous recombination (HR). AtBRCA1 contains a typical C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 26354897  48 ELMCPICLDMLKnTMTTKECLHRFCADCIITALRsGNKECPTCrKKLVSKRSLR 101
Cdd:cd23147   4 ELKCPICLSLFK-SAANLSCNHCFCAGCIGESLK-LSAICPVC-KIPATRRDTR 54

RING finger, HC subclass, found in tripartite motif-containing protein TRIM65 and similar proteins; TRIM65 is an E3 ubiquitin-protein ligase that interacts with the innate immune receptor MDA5, enhancing its ability to stimulate interferon-beta signaling. It functions as a potential oncogenic protein that negatively regulates p53 through ubiquitination, providing insight into the development of novel approaches targeting TRIM65 for non-small cell lung carcinoma (NSCLC) treatment, and also overcoming chemotherapy resistance. Moreover, TRIM65 negatively regulates microRNA-driven suppression of mRNA translation by targeting TNRC6 proteins for ubiquitination and degradation. TRIM65 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 26354897  48 ELMCPICLDMLKNTMTTkECLHRFCADCIITALR---SGNKECPTCRKKLVSKRSLR 101
Cdd:cd16609   3 ELTCSICLGLYQDPVTL-PCQHSFCRACIEDHWRqkdEGSFSCPECRAPFPEGPTLE 58

RING finger, H2 subclass, found in RING finger protein 103 (RNF103) and similar proteins; RNF103, also known as KF-1 or zinc finger protein 103 homolog (Zfp-103), is an endoplasmic reticulum (ER)-resident E3 ubiquitin-protein ligase that is widely expressed in many different organs, including brain, heart, kidney, spleen, and lung. It is involved in the ER-associated degradation (ERAD) pathway by interacting with components of the ERAD pathway, including Derlin-1 and VCP. RNF103 contains several hydrophobic regions at its N-terminal and middle regions, as well as a C-terminal C3H2C3-type RING-H2 finger.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 26354897  51 CPICLDMLKNTMTTK--ECLHRFCADCIITALRSGNKECPTCRKKL 94
Cdd:cd16473   7 CAICLENYQNGDLLRglPCGHVFHQNCIDVWLERDNHCCPVCRWPV 52

RING finger found in polycomb group RING finger protein 6 (PCGF6) and similar proteins; PCGF6, also known as Mel18 and Bmi1-like RING finger (MBLR), or RING finger protein 134 (RNF134), 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 noncanonical Polycomb repressive complex 1 (PRC1)-like L3MBTL2 complex, which is composed of some canonical components, such as RNF2, CBX3, CXB4, CXB6, CXB7, and CXB8, as well as some noncanonical components, such as L3MBTL2, E2F6, WDR5, HDAC1, and RYBP, and plays a critical role in epigenetic transcriptional silencing in higher eukaryotes. Like other PCGF homologs, PCGF6 possesses the transcriptional repression activity, and also 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, PCGF6 can regulate the enzymatic activity of JARID1d/KDM5D, a trimethyl H3K4 demethylase, through direct interaction. Furthermore, PCGF6 is expressed predominantly in meiotic and post-meiotic male germ cells and may play important roles in mammalian male germ cell development. It also regulates mesodermal lineage differentiation in mammalian embryonic stem cells (ESCs) and functions in induced pluripotent stem (iPS) reprogramming. The activity of PCGF6 is found to be regulated by cell cycle dependent phosphorylation. PCGF6 contains a C3HC4-type RING-HC finger.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*...
gi 26354897  43 RSLHSELMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNKeCPTC 90
Cdd:cd16738   2 AELNPYILCSICKGYFIDATTITECLHTFCKSCIVRHFYYSNR-CPKC 48

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 26354897    47 SELMCPICLDMLKNTMTTkECLHR-FCADCIITaLRSGNKECPTCRKK 93
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLL-PCGHLcLCEECAER-LLRKKKKCPICRQP 46

H2 subclass of RING (RING-H2) fingers 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 different Cys/His patterns while some lack a single Cys or His residue at typical Zn ligand positions (the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can indeed chelate Zn in a RING finger as well). This family corresponds to the H2 subclass of RING (RING-H2) finger proteins that are characterized by containing C3H2C3-type canonical RING-H2 fingers or noncanonical RING-H2 finger variants, including C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type modified RING-H2 fingers. The canonical RING-H2 finger has been defined as C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-H-X2-C-X(4-48)-C-X2-C, X is any amino acid and the number of X residues varies in different fingers. It binds two Zn ions in a unique "cross-brace" arrangement, which distinguishes it from tandem zinc fingers and other similar motifs. RING-H2 finger 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 serves as a scaffold 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 26354897  51 CPICLDML--KNTMTTKECLHRFCADCIITALRSGNKECPTCR 91
Cdd:cd16448   1 CVICLEEFeeGDVVRLLPCGHVFHLACILRWLESGNNTCPLCR 43

RING finger, HC subclass, found in RING finger protein 180 (RNF180) and similar proteins; RNF180, also known as Rines, is a membrane-bound E3 ubiquitin-protein ligase well conserved among vertebrates. It is a critical regulator of the monoaminergic system, as well as emotional and social behavior. It interacts with brain monoamine oxidase A (MAO-A) and targets it for ubiquitination and degradation. It also functions as a novel tumor suppressor in gastric carcinogenesis. The hypermethylated CpG site count of the RNF180 DNA promoter can be used to predict survival of gastric cancer. RNF180 contains a novel conserved dual specificity protein phosphatase Rines conserved (DSPRC) domain, a basic coiled-coil domain, a C3HC4-type RING-HC finger, and a C-terminal hydrophobic region that is predicted to be a transmembrane domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*...
gi 26354897  47 SELMCPICLDMLKNTMTTKECLHRFCADCI--ITALRSGNKECPTCRK 92
Cdd:cd16554   1 ESLTCPVCLDLYYDPYMCYPCGHIFCEPCLrqLAKSSPKNTPCPLCRT 48

RING finger, HC subclass, found in tripartite motif-containing protein 39 (TRIM39) and similar proteins; TRIM39, also known as RING finger protein 23 (RNF23) or testis-abundant finger protein, is an E3 ubiquitin-protein ligase that plays a role in controlling DNA damage-induced apoptosis through inhibition of the anaphase promoting complex (APC/C), a multiprotein ubiquitin ligase that controls multiple cell cycle regulators, including cyclins, geminin, and others. TRIM39 also functions as a regulator of several key processes in the proliferative cycle. It directly regulates p53 stability. It modulates cell cycle progression and DNA damage responses via stabilizing p21. Moreover, TRIM39 negatively regulates the nuclear factor kappaB (NFkappaB)-mediated signaling pathway through stabilization of Cactin, an inhibitor of NFkappaB- and Toll-like receptor (TLR)-mediated transcription, which is induced by inflammatory stimulants such as tumor necrosis factor alpha. Furthermore, TRIM39 is a MOAP-1-binding protein that can promote apoptosis signaling through stabilization of MOAP-1 via the inhibition of its poly-ubiquitination process. TRIM39 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 26354897  48 ELMCPICLDMLKNTMTTkECLHRFCADCIIT--ALRSGNKECPTC 90
Cdd:cd16601   1 EASCSLCKEYLKDPVII-ECGHNFCRACITRfwEELDGDFPCPQC 44

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 26354897  48 ELMCPICLDMLKNTMTTKeCLHRFCADCIITALRSGNKeCPTCRKKL 94
Cdd:cd16514   1 DLECSLCLRLLYEPVTTP-CGHTFCRACLERCLDHSPK-CPLCRTSL 45

RING finger, HC subclass, found in ubiquitin-like PHD and RING finger domain-containing protein 1 (UHRF1); UHRF1, also known as inverted CCAAT box-binding protein of 90 kDa, nuclear protein 95, nuclear zinc finger protein Np95 (Np95), RING finger protein 106, transcription factor ICBP90, or E3 ubiquitin-protein ligase UHRF1, is a unique chromatin effector protein that integrates the recognition of both histone PTMs and DNA methylation. It is essential for cell proliferation and plays a critical role in the development and progression of many human carcinomas, such as laryngeal squamous cell carcinoma (LSCC), gastric cancer (GC), esophageal squamous cell carcinoma (ESCC), colorectal cancer, prostate cancer, and breast cancer. UHRF1 can acts as a transcriptional repressor through its binding to histone H3 when it is unmodified at Arg2. Its overexpression in human lung fibroblasts results in downregulation of expression of the tumor suppressor pRB. It also plays a role in transcriptional repression of the cell cycle regulator p21. Moreover, UHRF1-dependent repression of factors can facilitate the G1-S transition. It interacts with Tat-interacting protein of 60 kDa (TIP60) and induces degradation-independent ubiquitination of TIP60. It is also a N-methylpurine DNA glycosylase (MPG)-interacting protein that binds MPG in a p53 status-independent manner in the DNA base excision repair (BER) pathway. In addition, UHRF1 functions as an epigenetic regulator that is important for multiple aspects of epigenetic regulation, including maintenance of DNA methylation patterns and recognition of various histone modifications. UHRF1 contains an N-terminal ubiquitin-like domain (UBL), a tandem Tudor domain (TTD), a plant homeodomain (PHD) domain, a SET and RING finger associated (SRA) domain, and a C-terminal C3HC4-type RING-HC finger. It specifically binds to hemimethylated DNA, double-stranded CpG dinucleotides, and recruits the maintenance methyltransferase DNMT1 to its hemimethylated DNA substrate through its SRA domain. UHRF1-dependent H3K23 ubiquitylation has an essential role in maintenance DNA methylation and replication. The tandem Tudor domain directs UHRF1 binding to the heterochromatin mark histone H3K9me3 and the PHD domain targets UHRF1 to unmodified histone H3 in euchromatic regions. The RING-HC finger exhibits both autocatalytic E3 ubiquitin (Ub) ligase activity and activity against histone H3 and DNMT1.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 26354897  49 LMCPICLDMLKNTMTTKeCLHRFCADCIITALRSGNKECPTCRKKLVSKRSLRPDPNFDALISKIYP 115
Cdd:cd16769  13 FQCICCQELVFRPITTV-CQHNVCKDCLDRSFRAQVFSCPACRYDLGRSYAMQVNQPLQTVLNQLFP 78

RING finger, H2 subclass, found in Tetratricopeptide repeat protein 3 (TTC3) and similar proteins; TTC3, also known as protein DCRR1, TPR repeat protein D, TPR repeat protein 3, or RING finger protein 105 (RNF105), is an E3 ubiquitin-protein ligase encoded by a gene within the Down syndrome (DS) critical region on chromosome 21. It affects differentiation and Golgi compactness in neurons through specific actin-regulating pathways. It inhibits the neuronal-like differentiation of pheocromocytoma cells by activating RhoA and by binding to Citron proteins. TTC3 is an Akt-specific E3 ligase that binds to phosphorylated Akt and facilitates its ubiquitination and degradation within the nucleus. It contains four N-terminal TPR motifs, a potential coiled-coil region and a Citron binding region in the central part, and a C-terminal C3H2C2-type RING-H2 finger.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 26354897  51 CPICLDMLKNTMTTK-ECLHRFCADCIITALRSgNKECPTCRKKL 94
Cdd:cd16481   2 CIICHDDLKPDQLAKlECGHIFHKECIKQWLKE-QSTCPTCRVHV 45

RING finger, HC subclass, found in tripartite motif-containing protein TRIM4 and similar proteins; TRIM4 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, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM4, also known as RING finger protein 87 (RNF87), is a cytoplasmic E3 ubiquitin-protein ligase that has recently evolved and is present only in higher mammals. It transiently interacts with mitochondria, induces mitochondrial aggregation and sensitizes the cells to hydrogen peroxide (H2O2) induced death. Its interaction with peroxiredoxin 1 (PRX1) is critical for the regulation of H2O2 induced cell death. Moreover, TRIM4 functions as a positive regulator of RIG-I-mediated type I interferon induction. It regulates the K63-linked ubiquitination of RIG-1 and assembly of antiviral signaling complex at the mitochondria.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 26354897  45 LHSELMCPICLDMLKNTMTTkECLHRFCADCIIT--ALRSGNKECPTCRKKlVSKRSLRPD 103
Cdd:cd16590   3 IQEELTCPICLDYFQDPVSI-ECGHNFCRGCLHRnwAPGGGPFPCPECRHP-SAPAALRPN 61

RING finger, HC subclass, found in SH3 domain-containing RING finger protein 1 (SH3RF1) and similar proteins; SH3RF1, also known as plenty of SH3s (POSH), RING finger protein 142 (RNF142), or SH3 multiple domains protein 2 (SH3MD2), is a trans-Golgi network-associated pro-apoptotic scaffold protein with E3 ubiquitin-protein ligase activity. It also plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and c-Jun N-terminal kinase (JNK) mediated apoptosis, linking Rac1 to downstream components. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. Moreover, SH3RF1 assembles an inhibitory complex with the actomyosin regulatory protein Shroom3, which links to the actin-myosin network to regulate neuronal process outgrowth. It also forms a complex with apoptosis-linked gene-2 (ALG-2) and ALG-2-interacting protein (ALIX/AIP1) in a calcium-dependent manner to play a role in the regulation of the JNK pathway. Furthermore, direct interaction of SH3RF1 and another molecular scaffold JNK-interacting protein (JIP) is required for apoptotic activation of JNKs. Interaction of SH3RF1 and E3 ubiquitin-protein isopeptide ligases, Siah proteins, further promotes JNK activation and apoptosis. In addition, SH3RF1 binds to and degrades TAK1, a crucial activator of both the JNK and the Relish signaling pathways. SH3RF1 contains an N-terminal C3HC4-type RING-HC finger responsible for the E3 ligase activity and four Src Homology 3 (SH3) domains, which are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 26354897  49 LMCPICLDMLKNTMTTKECLHRFCADCIITALRSGNK-ECPTCR 91
Cdd:cd16748   3 LECPVCLERLDATAKVLPCQHTFCRRCLLGIVGSRSElRCPECR 46