RING finger (Really Interesting New Gene) domain and U-box domain superfamily; 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). C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type RING fingers are closely related to RING-HC fingers. In contrast, C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type RING fingers are more closely related to RING-H2 fingers. However, not all RING finger-containing proteins display regular RING finger features, and the RING finger family has turned out to be multifarious. The degenerate RING fingers of the Siz/PIAS RING (SP-RING) family proteins and sporulation protein RMD5, are characterized by lacking the second, fifth, and sixth Zn2+ ion-coordinating residues. They bind only one Zn2+ ion. On the other hand, the RING fingers of the human APC11 and RBX1 proteins can bind a third Zn atom since they harbor four additional Zn ligands. U-box is a modified form of the RING finger domain that lacks metal chelating Cys and His residues. It resembles the cross-brace RING structure consisting of three beta-sheets and a single alpha-helix, which would be stabilized by salt bridges instead of chelated metal ions. U-box proteins are widely distributed among eukaryotic organisms and show a higher prevalence in plants than in other organisms. RING finger/U-box-containing proteins are 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 enable efficient transfer of ubiquitin from E2 to the substrates.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 17533953   4 LKCGVCTEDYSNVITNRhPKNLTCGHSICKACSSKLVSN--FKILCPFCRKTT 54
Cdd:cd16516   1 LECKVCFEKYSHQQEHR-PRNLPCGHVLCRECVTALAHPrrSKLECPFCRKAC 52

RING finger, HC subclass, found in malin and similar proteins; Malin ("mal" for seizure in French), also known as NHL repeat-containing protein 1 (NHLRC1), or EPM2B, is a nuclear E3 ubiquitin-protein ligase that ubiquitinates and promotes the degradation of laforin (EPM2A encoding protein phosphatase). Malin and laforin operate as a functional complex that play key roles in regulating cellular functions such as glycogen metabolism, unfolded cellular stress response, and proteolytic processes. They act as pro-survival factors that negatively regulate the Hipk2-p53 cell death pathway. They also negatively regulate cellular glucose uptake by preventing plasma membrane targeting of glucose transporters. Moreover, they degrade polyglucosan bodies in concert with glycogen debranching enzyme and brain isoform glycogen phosphorylase. Furthermore, they, together with Hsp70, form a new functional complex that suppress the cellular toxicity of misfolded proteins by promoting their degradation through the ubiquitin-proteasome system. Defects in either malin or laforin may cause Lafora disease (LD), a fatal form of teenage-onset autosomal recessive progressive myoclonus epilepsy. In addition, malin may have function, independent of laforin, in lysosomal biogenesis and/or lysosomal glycogen disposal. Malin contains six NHL-repeat protein-protein interaction domains and a C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 17533953   4 LKCGVCTEDYSNVITNRhPKNLTCGHSICKACSSKLVSN--FKILCPFCRKTT 54
Cdd:cd16516   1 LECKVCFEKYSHQQEHR-PRNLPCGHVLCRECVTALAHPrrSKLECPFCRKAC 52

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 17533953      6 CGVCTEDYSNVitnrhPKNLTCGHSICKACSSKLVSNFKILCPFC 50
Cdd:smart00184   1 CPICLEEYLKD-----PVILPCGHTFCRSCIRKWLESGNNTCPIC 40

zinc-RING finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 17533953     5 KCGVCTEDYSNvitNRHPKNLTCGHSICKACSSKLVSNFKilCPFCRK 52
Cdd:pfam14634   1 HCNKCFKELSK---TRPFYLTSCGHIFCEECLTRLLQERQ--CPICKK 43

RING finger, HC subclass, found in malin and similar proteins; Malin ("mal" for seizure in French), also known as NHL repeat-containing protein 1 (NHLRC1), or EPM2B, is a nuclear E3 ubiquitin-protein ligase that ubiquitinates and promotes the degradation of laforin (EPM2A encoding protein phosphatase). Malin and laforin operate as a functional complex that play key roles in regulating cellular functions such as glycogen metabolism, unfolded cellular stress response, and proteolytic processes. They act as pro-survival factors that negatively regulate the Hipk2-p53 cell death pathway. They also negatively regulate cellular glucose uptake by preventing plasma membrane targeting of glucose transporters. Moreover, they degrade polyglucosan bodies in concert with glycogen debranching enzyme and brain isoform glycogen phosphorylase. Furthermore, they, together with Hsp70, form a new functional complex that suppress the cellular toxicity of misfolded proteins by promoting their degradation through the ubiquitin-proteasome system. Defects in either malin or laforin may cause Lafora disease (LD), a fatal form of teenage-onset autosomal recessive progressive myoclonus epilepsy. In addition, malin may have function, independent of laforin, in lysosomal biogenesis and/or lysosomal glycogen disposal. Malin contains six NHL-repeat protein-protein interaction domains and a C3HC4-type RING-HC finger.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 17533953   4 LKCGVCTEDYSNVITNRhPKNLTCGHSICKACSSKLVSN--FKILCPFCRKTT 54
Cdd:cd16516   1 LECKVCFEKYSHQQEHR-PRNLPCGHVLCRECVTALAHPrrSKLECPFCRKAC 52

RING finger, HC subclass, found in tripartite motif-containing protein 32 (TRIM32) and similar proteins; TRIM32, also known as 72 kDa Tat-interacting protein, zinc finger protein HT2A, or BBS11, is an E3 ubiquitin-protein ligase that promotes degradation of several targets, including actin, PIASgamma, Abl interactor 2, dysbindin, X-linked inhibitor of apoptosis (XIAP), p73 transcription factor, thin filaments and Z-bands during fasting. It plays important roles in neuronal differentiation of neural progenitor cells, as well as in controlling cell fate in skeletal muscle progenitor cells. It reduces PI3K-Akt-FoxO signaling in muscle atrophy by promoting plakoglobin-PI3K dissociation. It also functions as a pluripotency-reprogramming roadblock that facilitates cellular transition towards differentiation by modulating the levels of Oct4 and cMyc. Moreover, TRIM32 is an intrinsic influenza A virus (IAV) restriction factor which senses and targets the polymerase basic protein 1 (PB1) for ubiquitination and protein degradation. It also plays a significant role in mediating the biological activity of the HIV-1 Tat protein in vivo, binds specifically to the activation domain of HIV-1 Tat, and can also interact with the HIV-2 and EIAV Tat proteins in vivo. Furthermore, TRIM32 regulates myoblast proliferation by controlling turnover of NDRG2 (N-myc downstream-regulated gene). It negatively regulates tumor suppressor p53 to promote tumorigenesis. It also facilitates degradation of MYCN on spindle poles and induces asymmetric cell division in human neuroblastoma cells. In addition, TRIM32 plays important roles in regulation of hyperactivities and positively regulates the development of anxiety and depression disorders induced by chronic stress. It also plays a role in regeneration by affecting satellite cell cycle progression via modulation of the SUMO ligase PIASy (PIAS4). Defects in TRIM32 leads to limb-girdle muscular dystrophy type 2H (LGMD2H), sarcotubular myopathies (STM) and Bardet-Biedl syndrome. TRIM32 belongs to the C-VII subclass of the TRIM (tripartite motif)-NHL family that is 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 domain, as well as a NHL (named after proteins NCL-1, HT2A and Lin-41 that contain repeats folded into a six-bladed beta propeller) repeat domain positioned C-terminal to the RBCC domain. The NHL domain mediates the interaction with Argonaute proteins and consequently allows TRIM32 to modulate the activity of certain miRNAs.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 17533953   4 LKCGVCTEDYSNviTNRHPKNLTCGHSICKACSSKLVSNFKIL---CPFCRK 52
Cdd:cd16587   1 LECPICLESFDE--GQLRPKLLHCGHTICEQCLEKLLASLSINgvrCPFCRK 50

Modified RING finger, HC subclass (C3HC3D-type), found in Roquin-1, Roquin-2, and similar proteins; The ROQUIN family includes Roquin-1, Roquin-2, and similar proteins, which localize to the cytoplasm and upon stress, are concentrated in stress granules. They may play essential roles in preventing T-cell-mediated autoimmune disease and in microRNA-mediated repression of inducible costimulator (Icos) mRNA. They function as E3 ubiquitin ligases consisting of an N-terminal modified C3HC3D-type RING-HC finger with a potential E3 activity, a highly conserved ROQ domain required for RNA binding and localization to stress granules, and a CCCH-type zinc finger involved in RNA recognition.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 17533953   3 FLKCGVCTEDYSNviTNRHPKNLTCGHSICKACSSKLVSNfkiLCPF 49
Cdd:cd16638   1 FLSCPVCTNEFDG--TQRKPISLGCGHTVCKTCLSKLHRK---QCPF 42

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 17533953   4 LKCGVCTEDYSNVITnrhpknLTCGHSICKACSSKLVSNFKILCPFC 50
Cdd:cd16449   1 LECPICLERLKDPVL------LPCGHVFCRECIRRLLESGSIKCPIC 41

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 17533953      6 CGVCTEDYSNVitnrhPKNLTCGHSICKACSSKLVSNFKILCPFC 50
Cdd:smart00184   1 CPICLEEYLKD-----PVILPCGHTFCRSCIRKWLESGNNTCPIC 40

RING finger, HC subclass, found in RING finger protein RNF224 and similar proteins; RNF224 is uncharacterized C3HC4-type RING-HC finger-containing proteins. It may function as an E3 ubiquitin-protein ligase.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 17533953   4 LKCGVCTEDYSnvITNRHPKNLTCGHSICKACSSKL--VSNFK--ILCPFCRKTT 54
Cdd:cd16565   1 LDCIICYSAYD--LSTRLPRRLYCGHTFCQACLKRLdtVINEQrwIPCPQCRQNT 53

Modified RING finger, HC subclass (C3HC3D-type), found in Roquin-1; Roquin-1, also known as RING finger and C3H zinc finger protein 1 (RC3H1), or RING finger protein 198 (RNF198), is a ubiquitously expressed RNA-binding protein essential for degradation of inflammation-related mRNAs and maintenance of immune homeostasis. It is localized in cytoplasmic granules and binds to the 3' untranslated region (3'UTR) of inducible costimulator (Icos) mRNA to post-transcriptionally repress its expression. Roquin-1 interacts with the 3'UTR of tumor necrosis factor receptor superfamily member 4 (TNFRSF4) and tumor-necrosis factor-alpha (TNFalpha), and post-transcriptionally regulates A20 mRNA and modulates the activity of the IKK/NF-kappaB pathway. Moreover, Roquin-1 shares functions with its paralog Roquin-2 in the repression of mRNAs controlling T follicular helper cells and systemic inflammation. Roquin-1 contains an N-terminal modified C3HC3D-type RING-HC finger with a potential E3 ubiquitin-ligase function, a highly conserved ROQ domain required for RNA binding and localization to stress granules, and a CCCH-type zinc finger that is involved in RNA recognition, typically contacting AU-rich elements. In addition, both N- and C-terminal to the ROQ domain are combined to form a HEPN (higher eukaryotes and prokaryotes nucleotide-binding) domain that is highly likely to function as an RNA-binding domain.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 17533953   3 FLKCGVCTEDYSNVItnRHPKNLTCGHSICKACSSKLvsnFKILCPF 49
Cdd:cd16781   6 FLSCPICTQTFDETI--RKPISLGCGHTVCKMCLNKL---HRKACPF 47

zinc-RING finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 17533953     5 KCGVCTEDYSNvitNRHPKNLTCGHSICKACSSKLVSNFKilCPFCRK 52
Cdd:pfam14634   1 HCNKCFKELSK---TRPFYLTSCGHIFCEECLTRLLQERQ--CPICKK 43

RING finger, HC subclass, found in tripartite motif-containing protein TRIM2, TRIM3, and similar proteins; TRIM2, also known as RING finger protein 86 (RNF86), is an E3 ubiquitin-protein ligase that ubiquitinates the neurofilament light chain, a component of the intermediate filament in axons. Loss of function of TRIM2 results in early-onset axonal neuropathy. TRIM3, also known as brain-expressed RING finger protein (BERP), RING finger protein 97 (RNF97), or RING finger protein 22 (RNF22), is an E3 ubiquitin-protein ligase involved in the pathogenesis of various cancers. It also plays an important role in the central nervous system (CNS). In addition, TRIM3 may be involved in vesicular trafficking via its association with the cytoskeleton-associated-recycling or transport (CART) complex that is necessary for efficient transferrin receptor recycling, but not for epidermal growth factor receptor (EGFR) degradation. Both TRIM2 and TRIM3 belong to the C-VII subclass of the TRIM (tripartite motif)-NHL family that is 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 domain, as well as a NHL (named after proteins NCL-1, HT2A and Lin-41 that contain repeats folded into a six-bladed beta propeller) repeat domain positioned C-terminal to the RBCC domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 17533953   3 FLKCGVCTEDYSNvitnrhPKNLTCGHSICKACSSKLV--SNFKILCPFCR 51
Cdd:cd16586   1 FLSCGICLERYKN------PKVLPCLHTFCERCLQNYIpaESLSLSCPVCR 45

Ring finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 17533953     6 CGVCTEDYSNvitNRHPKNLTCGHSICKACSSKLVSNfKILCPFCR 51
Cdd:pfam13639   3 CPICLEEFEE---GDKVVVLPCGHHFHRECLDKWLRS-SNTCPLCR 44

RING finger, HC subclass, found in tripartite motif-containing protein TRIM50, TRIM73, TRIM74 and similar proteins; TRIM50 is a stomach-specific E3 ubiquitin-protein ligase, encoded by the Williams-Beuren syndrome (WBS) TRIM50 gene, which regulates vesicular trafficking for acid secretion in gastric parietal cells. It colocalizes, interacts with, and increases the level of p62/SQSTM1, a multifunctional adaptor protein implicated in various cellular processes including the autophagy clearance of polyubiquitinated protein aggregates. It also promotes the formation and clearance of aggresome-associated polyubiquitinated proteins through the interaction with histone deacetylase 6 (HDAC6), a tubulin specific deacetylase that regulates microtubule-dependent aggresome formation. TRIM50 can be acetylated by PCAF and p300. TRIM50 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. This subfamily also includes two paralogs of TRIM50, tripartite motif-containing protein 73 (TRIM73), also known as tripartite motif-containing protein 50B (TRIM50B), and tripartite motif-containing protein 74 (TRIM74), also known as tripartite motif-containing protein 50C (TRIM50C), both of which are WBS-related genes encoding proteins that may also act as E3 ligases. In contrast with TRIM50, TRIM73 and TRIM74 belong to the C-V subclass of TRIM family of proteins that are defined by N-terminal RBCC domains only.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 17533953   4 LKCGVCTEDYsnvitnRHPKNLTCGHSICKACSSKLVSNF--KILCPFCRK 52
Cdd:cd16605   1 LLCPICLEVF------KEPLMLQCGHSYCKSCLVSLSGELdgQLLCPVCRQ 45

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

                        10        20        30
                ....*....|....*....|....*....|.
gi 17533953  22 PKNLTCGHSICKACSSKLVSNFKILCPFCRK 52
Cdd:cd16550  13 PVTLPCNHTLCMPCFQSTVEKASLCCPLCRL 43

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        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 17533953   3 FLKCGVCTEDYsnvitnRHPKNLTCGHSICKACSSKLVSNFKILCPFCRKTTELREN 59
Cdd:cd16584   1 FLACKICLEQL------RAPKTLPCLHTYCQDCLAQLADGGRVRCPECRETVPVPPE 51

RING finger, HC subclass, found in tripartite motif-containing proteins TRIM9, TRIM67, and similar proteins; Tripartite motif-containing proteins TRIM9 and TRIM67 belong to the C-I subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, consisting of three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a COS (carboxyl-terminal subgroup one signature) box, a fibronectin type III (FN3) domain, and a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain. TRIM9 (the human ortholog of rat Spring), also known as RING finger protein 91 (RNF91), is a brain-specific E3 ubiquitin-protein ligase collaborating with an E2 ubiquitin conjugating enzyme UBCH5b. TRIM9 plays an important role in the regulation of neuronal functions and participates in neurodegenerative disorders through its ligase activity. TRIM67, also known as TRIM9-like protein (TNL), is a protein selectively expressed in the cerebellum. It interacts with PRG-1, an important molecule in the control of hippocampal excitability dependent on presynaptic LPA2 receptor signaling, and 80K-H, also known as glucosidase II beta, a protein kinase C substrate.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 17533953   4 LKCGVCTEDYSNvitnrhPKNLTCGHSICKACSsklvSNFKILCPFCRK 52
Cdd:cd16576   4 LKCPVCGSLFTE------PVILPCSHNLCLGCA----LNIQLTCPICHK 42

RING finger, HC subclass, found in RING finger protein 152 (RNF152) and similar proteins; RNF152 is a lysosome-anchored E3 ubiquitin-protein ligase involved in apoptosis. It is polyubiquitinated through K48 linkage. It negatively regulates the activation of the mTORC1 pathway by targeting RagA GTPase for K63-linked ubiquitination. It interacts with and ubiquitinates RagA in an amino-acid-sensitive manner. The ubiquitination of RagA recruits its inhibitor GATOR1, a GAP complex for Rag GTPases, to the Rag complex, thereby inactivating mTORC1 signaling. RNF152 contains an N-terminal C3HC4-type RING-HC finger and a C-terminal transmembrane domain, both of which are responsible for its E3 ligase activity.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 17533953   4 LKCGVCTEDYSnviTNRHPKNLTCGHSICKACSSKL-VSNFKILCPFCR 51
Cdd:cd16548   1 LECQICFNYYS---PRRRPKLLDCKHTCCSVCLQQMrTSQKDLRCPWCR 46

RING finger, HC subclass, found in RING finger protein 169 (RNF169) and similar proteins; RNF169 is an uncharacterized E3 ubiquitin-protein ligase paralogous to RNF168. It functions as a negative regulator of the DNA damage signaling cascade. RNF169 recognizes polyubiquitin structures but does not itself contribute to double-strand break (DSB)-induced chromatin ubiquitylation. It contributes to regulation of the DSB repair pathway utilization via functionally competing with recruiting repair factors, 53BP1 and RAP80-BRCA1, for association with RNF168-modified chromatin independent of its catalytic activity, limiting the magnitude of the RNF8/RNF168-dependent signaling response to DSBs. RNF169 contains an N-terminal C3HC4-type RING-HC finger and a C-terminal MIU (motif interacting with ubiquitin) domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 17533953   4 LKCGVCTEdysnviTNRHPKNLTCGHSICKACSSKLVSNFKI--LCPFCR 51
Cdd:cd16551   2 LTCAGCLE------VPVEPATLPCGHTLCRGCANRALDAAEAgpTCPRCR 45

RING finger, HC subclass, found in tripartite motif-containing protein 36 (TRIM36) and similar proteins; TRIM36, the human ortholog of mouse Haprin, also known as RING finger protein 98 (RNF98) or zinc-binding protein Rbcc728, is an E3 ubiquitin-protein ligase expressed in the germ plasm. It has been implicated in acrosome reaction, fertilization, and embryogenesis, as well as in carcinogenesis. TRIM36 functions upstream of Wnt/beta-catenin activation, and plays a role in controlling the stability of proteins regulating microtubule polymerization during cortical rotation, and subsequently dorsal axis formation. It is also potentially associated with chromosome segregation by interacting with the kinetochore protein centromere protein-H (CENP-H), and colocalizing with the microtubule protein alpha-tubulin. Its overexpression may cause chromosomal instability and carcinogenesis. It is, thus, a novel regulator affecting cell cycle progression. Moreover, TRIM36 plays a critical role in the arrangement of somites during embryogenesis. TRIM36 belongs to the C-I 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 COS (carboxyl-terminal subgroup one signature) box, a fibronectin type III (FN3) domain, a PRY domain and a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 17533953   4 LKCGVCTEDYSnvitnrHPKNLTCGHSICKACSSKLVSNFKilCPFCRKTTEL 56
Cdd:cd16756   4 LICPSCKELFT------HPLILPCQHSVCHKCVKELLTTFP--CPGCQHDVDL 48

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 17533953   4 LKCGVCTEDYSnvitnrHPKNLTCGHSICKAC-SSKLVSNFKILCPFCR 51
Cdd:cd16568   5 QECIICHEYLY------EPMVTTCGHTYCYTClNTWFKSNRSLSCPDCR 47