RING finger, HC subclass, found in Arabidopsis thaliana RING membrane-anchor proteins (AtRMAs) and similar proteins; AtRMAs, including AtRma1, AtRma2, and AtRma3, are endoplasmic reticulum (ER)-localized Arabidopsis homologs of human outer membrane of the ER-anchor E3 ubiquitin-protein ligase, RING finger protein 5 (RNF5). AtRMAs possess E3 ubiquitin ligase activity, and may play a role in the growth and development of Arabidopsis. The AtRMA1 and AtRMA3 genes are predominantly expressed in major tissues, such as cotyledons, leaves, shoot-root junction, roots, and anthers, while AtRMA2 expression is restricted to the root tips and leaf hydathodes. AtRma1 probably functions with the Ubc4/5 subfamily of E2. AtRma2 is likely involved in the cellular regulation of ABP1 expression levels through interacting with auxin binding protein 1 (ABP1). AtRMA proteins contain an N-terminal C3HC4-type RING-HC finger and a trans-membrane-anchoring domain in their extreme C-terminal region.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQLssvsvdqHQNNCPVCKS 93
Cdd:cd16745   1 FECNICLDLAQDPVVTLCGHLFCWPCLHKWLRRQS-------SQPECPVCKA 45

Ring finger; E3 ubiquitin-protein ligase activity is intrinsic to the RING domain of c-Cbl and is likely to be a general function of this domain; Various RING fingers exhibit binding activity towards E2 ubiquitin-conjugating enzymes (Ubc' s)

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*....
gi 30687607     44 CNICLDT-AHDPVVTLCGHLFCWPCIYKWLhvqlssvsvDQHQNNCPVC 91
Cdd:smart00184   1 CPICLEEyLKDPVILPCGHTFCRSCIRKWL---------ESGNNTCPIC 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        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 30687607    42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVqlssvsvdqhQNNCPVCKS 93
Cdd:TIGR00599  27 LRCHICKDFFDVPVLTSCSHTFCSLCIRRCLSN----------QPKCPLCRA 68

RING finger, HC subclass, found in Arabidopsis thaliana RING membrane-anchor proteins (AtRMAs) and similar proteins; AtRMAs, including AtRma1, AtRma2, and AtRma3, are endoplasmic reticulum (ER)-localized Arabidopsis homologs of human outer membrane of the ER-anchor E3 ubiquitin-protein ligase, RING finger protein 5 (RNF5). AtRMAs possess E3 ubiquitin ligase activity, and may play a role in the growth and development of Arabidopsis. The AtRMA1 and AtRMA3 genes are predominantly expressed in major tissues, such as cotyledons, leaves, shoot-root junction, roots, and anthers, while AtRMA2 expression is restricted to the root tips and leaf hydathodes. AtRma1 probably functions with the Ubc4/5 subfamily of E2. AtRma2 is likely involved in the cellular regulation of ABP1 expression levels through interacting with auxin binding protein 1 (ABP1). AtRMA proteins contain an N-terminal C3HC4-type RING-HC finger and a trans-membrane-anchoring domain in their extreme C-terminal region.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQLssvsvdqHQNNCPVCKS 93
Cdd:cd16745   1 FECNICLDLAQDPVVTLCGHLFCWPCLHKWLRRQS-------SQPECPVCKA 45

RING finger, HC subclass, found in RING finger protein 185 (RNF185) and similar proteins; RNF185 is an E3 ubiquitin-protein ligase of endoplasmic reticulum-associated degradation (ERAD) that targets cystic fibrosis transmembrane conductance regulator (CFTR). It controls the degradation of CFTR and CFTR F508del allele in a RING- and proteasome-dependent manner, but does not control that of other classical ERAD model substrates. It also negatively regulates osteogenic differentiation by targeting dishevelled2 (Dvl2), a key mediator of the Wnt signaling pathway, for degradation. Moreover, RNF185 regulates selective mitochondrial autophagy through interaction with the Bcl-2 family protein BNIP1. It also plays an important role in cell adhesion and migration through the modulation of cell migration by ubiquitinating paxillin. RNF185 contains a C3HC4-type RING-HC finger.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQLSsvsvdqhQNNCPVCKSNITITSLVPLYG 105
Cdd:cd16744   1 FECNICLDTAKDAVVSLCGHLFCWPCLHQWLETRPN-------RQVCPVCKAGISRDKVIPLYG 57

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        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKwlhvqlssvSVDQHQNNCPVCKSNITITSL 100
Cdd:cd16509   4 EECAICLDSLTNPVITPCAHVFCRRCICE---------VIQREKAKCPMCRAPLSASDL 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        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCKSNITITSLVPL 103
Cdd:cd16527   3 CSLCLEERRHPTATPCGHLFCWSCITEWC----------NEKPECPLCREPFQPQRLVPL 52

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        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 30687607  43 DCNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCKSNIT 96
Cdd:cd16561   4 ECSICLEDLNDPVKLPCDHVFCEECIRQWL----------PGQMSCPLCRTELP 47

RING-finger-containing E3 ubiquitin ligase [Posttranslational modification, protein turnover, chaperones];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30687607  24 KPNLTtaPTAGQANesgcFDCNICLDTAHDPVVTLCGHLFCWPCIykwlhvqLSSVSVDQHQnNCPVCKS 93
Cdd:COG5574 204 KKNGL--PFIPLAD----YKCFLCLEEPEVPSCTPCGHLFCLSCL-------LISWTKKKYE-FCPLCRA 259

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        50
                ....*....|....*....|....*....|....*....|....*....|
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvDQHQNNCPVC 91
Cdd:cd16449   1 LECPICLERLKDPVLLPCGHVFCRECIRRLL---------ESGSIKCPIC 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        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 30687607  40 GCFDCNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCKSNIT 96
Cdd:cd16504   1 NDFLCPICFDIIKEAFVTKCGHSFCYKCIVKHL----------EQKNRCPKCNFYLT 47

RING finger, HC subclass, found in Arabidopsis thaliana proteolysis 1 protein (PRT1) and similar proteins; PRT1, also called RING-type E3 ubiquitin transferase PRT1, is an E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of target proteins. It functions in the N-end rule pathway of protein degradation, where it specifically recognizes and ubiquitinates proteins with an N-terminal bulky aromatic amino acid (Phe). It does not act on aliphatic hydrophobic and basic N-terminal residues (Arg or Leu) containing proteins. PRT1 contains a typical C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVqlssvsvdQHQNNCPVCKS 93
Cdd:cd23132   3 FLCCICLDLLYKPVVLECGHVFCFWCVHRCMNG--------YDESHCPLCRR 46

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        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCKS 93
Cdd:cd16514   2 LECSLCLRLLYEPVTTPCGHTFCRACLERCL----------DHSPKCPLCRT 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        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  43 DCNICLDTAHDPVVTL--CGHLFCWPCIYKWlhvqlSSVSvdqhqNNCPVCK 92
Cdd:cd16574   3 SCPICLDRFENEKAFLdgCFHAFCFTCILEW-----SKVK-----NECPLCK 44

RING finger, HC subclass, found in RING finger and transmembrane domain-containing protein 2(RNFT2); RNFT2, also known as transmembrane protein 118 (TMEM118), is a multi-pass membrane protein containing a C3HC4-type RING-HC finger. Its biological role remains unclear.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 30687607  32 TAGQANESGCFdCNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCKSNITIT 98
Cdd:cd16742   5 TSQQCSEAGDI-CAICQAEFREPLILICQHVFCEECLCLWF----------DRERTCPLCRSVVVET 60

RING finger, HC subclass, found in tripartite motif-containing protein 62 (TRIM62) and similar proteins; TRIM62, also known as Ductal Epithelium Associated Ring Chromosome 1 (DEAR1), is a cytoplasmic E3 ubiquitin-protein ligase that was identified as a dominant regulator of acinar morphogenesis in the mammary gland. It is implicated in the inflammatory response of immune cells by regulating the Toll-like receptor 4 (TLR4) signaling pathway, leading to increased activity of the activator protein 1 (AP-1) transcription factor in primary macrophages. It is also involved in muscular protein homeostasis, especially during inflammation-induced atrophy, and may play a role in the pathogenesis of ICU-acquired weakness (ICUAW) by activating and maintaining inflammation in myocytes. Moreover, TRIM62 facilitates K27-linked poly-ubiquitination of CARD9 and also regulates CARD9-mediated anti-fungal immunity and intestinal inflammation. It also functions as a chromosome 1p35 tumor suppressor and negatively regulates transforming growth factor beta (TGFbeta)-driven epithelial-mesenchymal transition (EMT) by binding to and promoting the ubiquitination of SMAD3, a major effector of TGFbeta-mediated EMT. TRIM62 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 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKwlHvqlssvSVDQHQNNCPVCK 92
Cdd:cd16608   7 LLCSICLSIYQDPVSLGCEHYFCRQCITE--H------WSRSEHRDCPECR 49

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        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWlhvqlssvsVDQHQNNCPVCKSNI 95
Cdd:cd23138   3 LNCSFCMQLPERPVTTPCGHNFCLKCFQKW---------MGQGKKTCGTCRSPI 47

RING finger, HC subclass, found in tripartite motif-containing protein TRIM25 and similar proteins; TRIM25, also known as estrogen-responsive finger protein (EFP), RING finger protein 147 (RNF147), or RING-type E3 ubiquitin transferase, is an E3 ubiquitin/ISG15 ligase that is induced by estrogen and is therefore particularly abundant in placenta and uterus. TRIM25 regulates various cellular processes through E3 ubiquitin ligase activity, transferring ubiquitin and ISG15 to target proteins. It mediates K63-linked polyubiquitination of retinoic acid inducible gene I (RIG-I) that is crucial for downstream antiviral interferon signaling. It is also required for melanoma differentiation-associated gene 5 (MDA5) and mitochondrial antiviral signaling (MAVS, also known as IPS-1, VISA, Cardiff) mediated activation of nuclear factor-kappaB (NF-kappaB) and interferon production. Upon UV irradiation, TRIM25 interacts with mono-ubiquitinated PCNA and promotes its ISG15 modification (ISGylation), suggesting a crucial role in termination of error-prone translesion DNA synthesis. TRIM25 also functions as a novel regulator of p53 and Mdm2. It enhances p53 and Mdm2 abundance by inhibiting their ubiquitination and degradation in 26S proteasomes. Meanwhile, it inhibits p53's transcriptional activity and dampens the response to DNA damage, and is essential for medaka development and this dependence is rescued by silencing of p53. Moreover, TRIM25 is involved in the host cellular innate immune response against retroviral infection. It interferes with the late stage of feline leukemia virus (FeLV) replication. Furthermore, TRIM25 acts as an oncogene in gastric cancer. Its blockade by RNA interference inhibits migration and invasion of gastric cancer cells through transforming growth factor-beta (TGF-beta) signaling, suggesting it presents a novel target for the detection and treatment of gastric cancer. In addition, TRIM25 acts as an RNA-specific activator for Lin28a/TuT4-mediated uridylation. TRIM25 belongs to the C-IV subclass of 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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQLSSvsvdqhQNNCPVCK 92
Cdd:cd16597   8 CSICLELFKDPVTLPCGHNFCGVCIEKTWDSQHGS------EYSCPQCR 50

RING finger, HC subclass, found in RING finger protein 170 (RNF170) and similar proteins; RNF170, also known as putative LAG1-interacting protein, is an endoplasmic reticulum (ER) membrane-bound E3 ubiquitin-protein ligase that mediates ubiquitination-dependent degradation of type-I inositol 1,4,5-trisphosphate (IP3) receptors (ITPR1) via the endoplasmic-reticulum-associated protein degradation (ERAD) pathway. A point mutation (arginine to cysteine at position 199) in the RNF170 gene is linked with autosomal-dominant sensory ataxia (ADSA), a disease characterized by neurodegeneration in the posterior columns of the spinal cord. RNF170 contains a C3HC4-type RING-HC finger.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYK-WLH-VQLSSVSvdqhqnnCPVCKSNITItsLVPLY 104
Cdd:cd16553   4 CPICLQDARFPVETNCGHLFCGPCIITyWRHgSWLGAVS-------CPVCRQTVTL--LLPVF 57

RING finger, H2 subclass, found in the PA-TM-RING ubiquitin ligase family; The PA-TM-RING family represents a group of transmembrane-type E3 ubiquitin ligases, which has been characterized by an N-terminal transient signal peptide, a PA (protease-associated) domain, a TM (transmembrane) domain, as well as a C-terminal C3H2C3-type RING-H2 finger domain. It includes RNF13, RNF167, ZNRF4 (zinc and RING finger 4), GRAIL (gene related to anergy in lymphocytes)/RNF128, RNF130, RNF133, RNF148, RNF149 and RNF150 (which are more closely related), as well as RNF43 and ZNRF3, which have substantially longer C-terminal tail extensions compared with the others. PA-TM-RING proteins are expressed at low levels in all mammalian tissues and species, but they are not present in yeast. They play a common regulatory role in intracellular trafficking/sorting, suggesting that abrogation of their function may result in dysregulation of cellular signaling events in cancer.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 30687607  43 DCNICLDT--AHDPVVTL-CGHLFCWPCIYKWLHvqlssvsvdqHQNNCPVCK 92
Cdd:cd16454   1 TCAICLEEfkEGEKVRVLpCNHLFHKDCIDPWLE----------QHNTCPLCR 43

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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHvqlssvSVDQHQNNCPVC 91
Cdd:cd16567   3 CGICHEEAEDPVVARCHHVFCRACVKEYIE------SAPGGKVTCPTC 44

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 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQ 75
Cdd:cd16637   2 LTCHICLQPLVEPLDTPCGHTFCYKCLTNYLKIQ 35

RING finger, HC subclass, found in Arabidopsis thaliana protein BENZOIC ACID HYPERSENSITIVE 1 (BAH1) and similar proteins; This subfamily includes Arabidopsis thaliana BAH1 and BAH1-like. BAH1, also known as protein NITROGEN LIMITATION ADAPTATION (NLA), or RING-type E3 ubiquitin transferase BAH1, acts as an E3 ubiquitin-protein ligase that mediates E2-dependent protein ubiquitination. It plays a role in salicylic acid-mediated negative feedback regulation of salicylic acid (SA) accumulation. It may be involved in the overall regulation of SA, benzoic acid and phenylpropanoid biosynthesis. It controls the adaptability to nitrogen limitation by channeling the phenylpropanoid metabolic flux to the induced anthocyanin synthesis. BAH1-like, also known as RING finger protein 178, or RING-type E3 ubiquitin transferase BAH1-like, is a probable E3 ubiquitin-protein ligase. Members of this subfamily contain a typical C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCiykwlhvQLSSVSVDQHQN--------NCPVCKS 93
Cdd:cd23127  11 CSICLDTVFDPVALGCGHLFCNSC-------ACSAASVLIFQGlkaappeaKCPLCRQ 61

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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKwlHVQLSSVSvdqHQNNCPVCK 92
Cdd:cd16583   8 CPICQEPLKEAVSTDCGHLFCRMCLTQ--HAKKASAS---GVFSCPVCR 51

RING finger, HC subclass, found in ligand of numb protein X 3 (LNX3); LNX3, also known as PDZ domain-containing RING finger protein 3 (PDZRN3), or Semaphorin cytoplasmic domain-associated protein 3 (SEMACAP3), is an E3 ubiquitin-protein ligase that was first identified as a Semaphorin-binding partner. It is also responsible for the ubiquitination and degradation of Numb, a component of the Notch signaling pathway that functions in the specification of cell fates during development and is known to control cell numbers during neurogenesis in vertebrates. LNX3 acts as a negative regulator of osteoblast differentiation by inhibiting Wnt-beta-catenin signaling. LNX3 also plays an important role in neuromuscular junction formation. It interacts with and ubiquitinates the muscle specific tyrosine kinase (MuSK), thus promoting its endocytosis and negatively regulating the cell surface expression of this key regulator of postsynaptic assembly. LNX3 contains an N-terminal C3HC4-type RING-HC finger, two PDZ domains, and a C-terminal LNX3 homology (LNX3H) domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLhVQlssvsvdqhQNNCPV 90
Cdd:cd16718   5 FKCNLCNKVLEDPLTTPCGHVFCAGCVLPWV-VQ---------QGSCPV 43

RING finger, HC subclass, found in tripartite motif-containing protein 69 (TRIM69) and similar proteins; TRIM69, also known as RFP-like domain-containing protein trimless or RING finger protein 36 (RNF36), is a testis E3 ubiquitin-protein ligase that plays a specific role in apoptosis and may also play an important role in germ cell homeostasis during spermatogenesis. TRIM69 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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQlssvsvdQHQNNCPVCK 92
Cdd:cd16611   7 CPLCLDFFRDPVMLSCGHNFCQSCITGFWELQ-------AEDTTCPECR 48

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
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYK-WLHVQLSSVSVDQHQN-NCPVCKSNITITSLVP 102
Cdd:cd16595   8 CSICLDYFTDPVMTTCGHNFCRACIQLsWEKARGKKGRRKQKGSfPCPECREMSPQRNLRP 68

RING finger, HC subclass, found in RING finger and transmembrane domain-containing protein RNFT1, RNFT2, and similar proteins; Both RNFT1 and RNFT2 are multi-pass membrane proteins containing a C3HC4-type RING-HC finger. Their biological roles remain unclear.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLhvqlssvsvdQHQNNCPVCK 92
Cdd:cd16532   3 CPICQDEFKDPVVLRCKHIFCEDCVSEWF----------ERERTCPLCR 41

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        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  44 CNICLDTAHDPVV---TLCGHLFCWPCIYKWLHVQlssvsvdqhQNNCPVCK 92
Cdd:cd16448   1 CVICLEEFEEGDVvrlLPCGHVFHLACILRWLESG---------NNTCPLCR 43

RING finger, HC subclass, found in Ret finger protein-like 4B (RFPL4B) and similar proteins; RFPL4B, also called RING finger protein 211 (RNF211), is an uncharacterized RING finger protein containing a typical C3HC4-type RING-HC finger.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQLSSVSVdqhqnnCPVCK 92
Cdd:cd16623  11 CPICLDFFSHPISLSCAHIFCFDCIQKWMTKREDSILT------CPLCR 53

zinc finger of C3HC4-type, RING; This is a family of primate-specific Ret finger protein-like (RFPL) zinc-fingers of the C3HC4 type. Ret finger protein-like proteins are primate-specific target genes of Pax6, a key transcription factor for pancreas, eye and neocortex development. This domain is likely to be DNA-binding. This zinc-finger domain together with the RDM domain, pfam11002, forms a large zinc-finger structure of the RING/U-Box superfamily. RING-containing proteins are known to exert an E3 ubiquitin protein ligase activity with the zinc-finger structure being mandatory for binding to the E2 ubiquitin-conjugating enzyme.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 30687607    44 CNICLDTAHDPVVTLCGHLFCWPCIYKWlhvqlsSVSVDQHQNNCPVC 91
Cdd:pfam15227   1 CPICLDYLEKPVSIECGHSFCLSCINSL------QKEPDGESLLCPQC 42

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        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 30687607    42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVqlssvsvdqhQNNCPVCKS 93
Cdd:TIGR00599  27 LRCHICKDFFDVPVLTSCSHTFCSLCIRRCLSN----------QPKCPLCRA 68

RING finger, HC subclass, found in tripartite motif-containing protein 35 (TRIM35) and similar proteins; TRIM35, also known as hemopoietic lineage switch protein 5 (HLS5), is a putative hepatocellular carcinoma (HCC) suppressor that inhibits phosphorylation of pyruvate kinase isoform M2 (PKM2), which is involved in aerobic glycolysis of cancer cells and further suppresses the Warburg effect and tumorigenicity in HCC. It also negatively regulates Toll-like receptor 7 (TLR7)- and TLR9-mediated type I interferon production by suppressing the stability of interferon regulatory factor 7 (IRF7). Moreover, TRIM35 regulates erythroid differentiation by modulating globin transcription factor 1 (GATA-1) activity. TRIM35 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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYK-WLHvqlssvsvdQHQNNCPVCK 92
Cdd:cd16599   7 CPICYEPFREAVTLRCGHNFCKGCVSRsWER---------QPRAPCPVCK 47

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 30687607    44 CNICLDTAHDPVVTLCGHL-FCWPCiykwlhvqlsSVSVDQHQNNCPVCKSNIT 96
Cdd:pfam13920   5 CVICLDRPRNVVLLPCGHLcLCEEC----------AERLLRKKKKCPICRQPIE 48

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        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 30687607  41 CFDCNICLDT--AHDPVVTL-CGHLFCWPCIYKWLHvqlssvsvdQHQNNCPVCKSNI 95
Cdd:cd16473   4 CEECAICLENyqNGDLLRGLpCGHVFHQNCIDVWLE---------RDNHCCPVCRWPV 52

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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHVQlssvsvdqhQNNCPVCK 92
Cdd:cd16530   5 CQVCEHILADPVQTPCKHLFCRTCILKCLKVM---------GSYCPSCR 44

RING finger, HC subclass, found in RING finger protein 141 (RNF141) and similar proteins; RNF141, also known as zinc finger protein 230 (ZNF230), is a RING finger protein present primarily in the nuclei of spermatogonia, the acrosome, and the tail of spermatozoa. It may have a broad function during early development of vertebrates. It plays an important role in spermatogenesis, including spermatogenic cell proliferation and sperm maturation, as well as motility and fertilization. It also exhibits DNA binding activity. RNF141/ZNF230 gene mutations may be associated with azoospermia. RNF141 contains a C3HC4-type RING finger domain that may function as an activator module in transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 30687607  43 DCNICLDTAHDpVVTLCGHLFCWPCIYKWlhvqlssvSVDQHqnNCPVCK 92
Cdd:cd16545   2 ECCICMDRKAD-LILPCAHSYCQKCIDKW--------SDRHR--TCPICR 40

second 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 second one.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCI-YKWLHVQLS--------SVSVDQHQNNCPVCKSNIT 96
Cdd:cd23139   6 FGCQICKKVLSLPVSTPCGHNFCKACLeAKFAGIADVrdrgnggrSLRARKNVKPCPCCKTDIS 69

RING finger, HC subclass, found in Candida albicans transcriptional regulator of yeast form adherence 3 (TRY3) and similar proteins; TRY3 acts as a transcription factor required for yeast cell adherence to silicone substrate. It contains a typical C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKwlhvqlssvSVDQHQNNCPVCKS 93
Cdd:cd23137   3 YACPICMNVAWKPVRLECSHVFCLRCLVK---------AQKQKKDNCPLCRA 45

RING finger, HC subclass, found in tripartite motif-containing protein TRIM58 and similar proteins; TRIM58, also known as protein BIA2, is an erythroid E3 ubiquitin-protein ligase induced during late erythropoiesis. It binds and ubiquitinates the intermediate chain of the microtubule motor dynein (DYNC1LI1/DYNC1LI2), stimulating the degradation of the dynein holoprotein complex. It may participate in the erythroblast enucleation process through regulation of nuclear polarization. TRIM58 belongs to the C-IV subclass of 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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHvqlSSVSVDQHQNNCPVCKS 93
Cdd:cd16606   5 CPVCLDFLQEPVSVDCGHSFCLRCISEFCE---KSDSAQGGVYACPQCRG 51

RING finger, HC subclass, found in bifunctional apoptosis regulator (BAR); BAR, also known as RING finger protein 47, was originally identified as an inhibitor of Bax-induced apoptosis. It participates in the block of apoptosis induced by TNF-family death receptors (extrinsic pathway) and mitochondria-dependent apoptosis (intrinsic pathway). BAR is predominantly expressed by neurons in the central nervous system and is involved in the regulation of neuronal survival. It is an endoplasmic reticulum (ER)-associated RING-type E3 ubiquitin ligase that interacts with BI-1 protein and post-translationally regulates its stability, as well as functioning in ER stress. BAR contains an N-terminal C3HC4-type RING-HC finger, a SAM domain, a coiled-coil domain, and a C-terminal transmembrane (TM) domain. This model corresponds to the RING-HC finger responsible for the binding of ubiquitin conjugating enzymes (E2s).

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKWLHVqlssvsvdQHQNNCPVCK 92
Cdd:cd16497   2 FLCHCCYDLLVNPTTLNCGHSFCRHCLALWWKS--------SKKTECPECR 44

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        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 30687607  44 CNICLDTAHDPVVTL-CGHLFCWPCIYKWLhvqlssvsvDQHQNNCPVCKSNIT 96
Cdd:cd16503   5 CSICQDLLHDCVSLQpCMHNFCAACYSDWM---------ERSNTECPTCRATVQ 49

RING finger, HC subclass, found in BRCA1-associated RING domain protein 1 (BARD-1) and similar proteins; BARD-1 is a critical factor in BRCA1-mediated tumor suppression and may also serve as a target for tumorigenic lesions in some human cancers. It associates with BRCA1 (breast cancer-1) to form a heterodimeric BRCA1/BARD1 complex that is responsible for maintaining genomic stability through nuclear functions involving DNA damage signaling and repair, transcriptional regulation, and cell cycle control. The BRCA1/BARD1 complex catalyzes autoubiquitination of BRCA1 and trans ubiquitination of other protein substrates. Its E3 ligase activity is dramatically reduced in the presence of UBX domain protein 1 (UBXN1). BARD-1 contains an C3HC4-type RING-HC finger that binds BRCA1 at its N-terminus and three tandem ankyrin repeats and tandem BRCT repeat domains at its C-terminus. The BRCT repeats bind CstF-50 (cleavage stimulation factor) to modulate mRNA processing and RNAP II stability in response to DNA damage.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 30687607  44 CNICLDTAHDPVvTL--CGHLFCWPCIykwlhvqlssvsVDQHQNNCPVCK 92
Cdd:cd16496  18 CSRCASILKEPV-TLggCEHVFCRSCV------------GDRLGNGCPVCD 55

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
                ....*....|....*....|....*....|
gi 30687607  42 FDCNICLDTAHDPVVTLCGHLFCWPCIYKW 71
Cdd:cd16512   1 LKCKLCLGVLEEPLATPCGHVFCAGCVLPW 30

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        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 30687607  42 FDCNICLDTAHDPVVTL-CGHLFCWPCIYKWLhvQLSSvsvdqhqNNCPVCK 92
Cdd:cd16549   2 FSCPICLEVYHKPVVITsCGHTFCGECLQPCL--QVAS-------PLCPLCR 44

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 30687607  44 CNICLDTAHDPVVTLCGHLFCWPCIYKWLHvqlSSVSVDQHQNNCPVCK 92
Cdd:cd16581   5 CSICYNIFDDPKILPCSHTFCKNCLEKLLA---ASGYYLLASLKCPTCR 50