zinc-ribbon;

                          10        20        30
                  ....*....|....*....|....*....|....
gi 170172564   19 RFFCHFCKGEVNP---KLPEYICPRCDSGFIEEV 49
Cdd:pfam14369   2 RYWCHQCDRFVRIapsEDSDVACPRCGGGFVEEI 35

Ring finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 170172564  228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:pfam13639   2 ECPICLEEFEEGDKVVVLPCGHHFHRECLDKWLRSSNTCPLCR 44

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 170172564   229 CPVCKEDYtvEEKVRQLPCNHFFHSSCIVPWLELHD-TCPVC 269
Cdd:smart00184   1 CPICLEEY--LKDPVILPCGHTFCRSCIRKWLESGNnTCPIC 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        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 170172564  211 TSLPTVTvtqeQVNTGLECPVCKEDYTVEEKVrqlPCNHFFHSSCIVPWLELHDTCPVCRKS 272
Cdd:TIGR00599  15 TPIPSLY----PLDTSLRCHICKDFFDVPVLT---SCSHTFCSLCIRRCLSNQPKCPLCRAE 69

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRK 271
Cdd:cd16801    1 ECPVCKEDYTVGENVRQLPCNHLFHNDCIVPWLEQHDTCPVCRK 44

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
                 ....*....|....*....|....*....|....*....|...
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16454    1 TCAICLEEFKEGEKVRVLPCNHLFHKDCIDPWLEQHNTCPLCR 43

RING finger, H2 subclass, found in RING finger proteins RNF24, RNF122, and similar proteins; This subfamily includes RNF24, RNF122, and similar proteins. RNF24 is an intrinsic membrane protein localized in the Golgi apparatus. It specifically interacts with the ankyrin-repeats domains (ARDs) of TRPC1, -3, -4, -5, -6, and -7, and affects TRPC intracellular trafficking without affecting their activity. RNF122 is a RING finger protein associated with HEK 293T cell viability. It is localized to the endoplasmic reticulum (ER) and the Golgi apparatus, and overexpressed in anaplastic thyroid cancer cells. RNF122 functions as an E3 ubiquitin ligase that can ubiquitinate itself and undergo degradation through its RING finger in a proteasome-dependent manner. Both RNF24 and RNF122 contain an N-terminal transmembrane domain and a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd16469    3 CAVCLEEFKLKEELGVCPCGHAFHTKCLKKWLEVRNSCPICKSPV 47

Ring finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 170172564  228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:pfam13639   2 ECPICLEEFEEGDKVVVLPCGHHFHRECLDKWLRSSNTCPLCR 44

RING finger, H2 subclass, found in E3 ubiquitin-protein ligase RNF6, RNF12, and similar proteins; RNF6 is an androgen receptor (AR)-associated protein that induces AR ubiquitination and promotes AR transcriptional activity. RNF6-induced ubiquitination may regulate AR transcriptional activity and specificity by modulating cofactor recruitment. RNF6 is overexpressed in hormone-refractory human prostate cancer tissues and required for prostate cancer cell growth under androgen-depleted conditions. RNF6 also regulates local serine/threonine kinase LIM kinase 1 (LIMK1) levels in axonal growth cones. RNF6-induced LIMK1 polyubiquitination is mediated via K48 of ubiquitin and leads to proteasomal degradation of the kinase. RNF6 binds and upregulates the Inha promoter, and functions as a transcription regulatory protein in the mouse sertoli cell. It acts as a potential tumor suppressor gene involved in the pathogenesis of esophageal squamous cell carcinoma (ESCC). RNF12, also known as LIM domain-interacting RING finger protein, or RING finger LIM domain-binding protein (R-LIM), is an E3 ubiquitin-protein ligase encoded by gene RLIM that is crucial for normal embryonic development in some species and for normal X inactivation in mice. It thus functions as a major sex-specific epigenetic regulator of female mouse nurturing tissues. RNF12 is widely expressed during embryogenesis, and mainly localizes to the cell nucleus, where it regulates the levels of many proteins, including CLIM, LMO, HDAC2, TRF1, SMAD7, and REX1, by proteasomal degradation. Both RNF6 and RNF12 contain a well conserved C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16467    1 ECTICLGEYETGEKLRRLPCSHEFHSECVDRWLKENSSCPICR 43

RING finger, H2 subclass, found in protein E3 ubiquitin-protein ligase Praja-1, Praja-2, and similar proteins; This family includes two highly similar E3 ubiquitin-protein ligases, Praja-1 and Praja-2. Praja-1, also known as RING finger protein 70, is a RING-H2 finger ubiquitin ligase encoded by gene PJA1, a novel human X chromosome gene abundantly expressed in the brain. It has been implicated in bone and liver development, as well as memory formation and X-linked mental retardation (MRX). Praja-1 interacts with and activates the ubiquitin-conjugating enzyme UbcH5B, and shows E2-dependent E3 ubiquitin ligase activity. It is a 3-deazaneplanocin A (DZNep)-induced ubiquitin ligase that directly ubiquitinates individual polycomb repressive complex 2 (PRC2) subunits in a cell free system, which leads to their proteasomal degradation. It also plays an important role in neuronal plasticity, which is the basis for learning and memory. Moreover, Praja-1 ubiquitinates embryonic liver fodrin (ELF) and Smad3, but not Smad4, in a transforming growth factor-beta (TGF-beta)-dependent manner. It controls ELF abundance through ubiquitin-mediated degradation, and further regulates TGF-beta signaling, which plays a key role in the suppression of gastric carcinoma. Praja-1 also regulates the transcription function of the homeodomain protein Dlx5 by controlling the stability of Dlxin-1, via a ubiquitin-dependent degradation pathway. Praja-2, also known as RING finger protein 131, NEURODAP1, or KIAA0438, is an E2-dependent E3 ubiquitin ligase that interacts with and activates the ubiquitin-conjugating enzyme UbcH5B. It functions as an A-kinase anchoring protein (AKAP)-like E3 ubiquitin ligase that plays a critical role in controlling cyclic AMP (cAMP)-dependent PKA activity and pro-survival signaling, and further promotes cell proliferation and growth. Praja-2 is also involved in protein sorting at the postsynaptic density region of axosomatic synapses and possibly plays a role in synaptic communication and plasticity. Together with the AMPK-related kinase SIK2 and the CDK5 activator CDK5R1/p35, it forms a SIK2-p35-PJA2 complex that plays an essential role for glucose homeostasis in pancreatic beta cell functional compensation. Praja-2 ubiquitylates and degrades Mob, a core component of NDR/LATS kinase and a positive regulator of the tumor-suppressor Hippo signaling. Both Praja-1 and Praja-2 contain a potential nuclear localization signal (NLS) and a C-terminal C3H2C3-type RING-H2 motif.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd16465    2 CPICCSEYVKDEIATELPCHHLFHKPCITAWLQKSGTCPVCRHVL 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 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLEL-HDTCPVCR 270
Cdd:cd16448    1 CVICLEEFEEGDVVRLLPCGHVFHLACILRWLESgNNTCPLCR 43

RING finger, H2 subclass, found in RING finger protein 130 (RNF130) and similar proteins; RNF130, also known as Goliath homolog (H-Goliath), is a paralog of RNF128, also known as gene related to anergy in lymphocytes protein (GRAIL). It is a transmembrane E3 ubiquitin-protein ligase expressed in leukocytes. It has a self-ubiquitination property, and controls the development of T cell clonal anergy by ubiquitination. RNF130 contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C-terminal C3H2C3-type RING-H2 finger domain followed by a putative PEST sequence.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16803    3 CAVCIEGYKQNDVVRILPCKHVFHKSCVDPWLNEHCTCPMCK 44

RING finger, H2 subclass, found in RING finger protein 128 (RNF128) and similar proteins; This subfamily includes RING finger proteins RNF128, RNF133, RNF148, and similar proteins, which belong to a larger PA-TM-RING ubiquitin ligase family that has been characterized by containing an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C-terminal C3H2C3-type RING-H2 finger followed by a putative PEST sequence. RNF128, also known as gene related to anergy in lymphocytes protein (GRAIL), is a type 1 transmembrane E3 ubiquitin-protein ligase that is a critical regulator of adaptive immunity and development. It inhibits cytokine gene transcription, is expressed in anergic CD4+ T cells, and has been implicated in primary T cell activation, survival, and differentiation, as well as in T cell anergy and oral tolerance. It induces T cell anergy through the ubiquitination activity of its cytosolic RING finger. It regulates expression of the costimulatory molecule CD40L on CD4 T cells, and ubiquitinates the costimulatory molecule CD40 ligand (CD40L) during the induction of T cell anergy. Moreover, RNF128 interacts with the luminal/extracellular portion of both CD151 and the related tetraspanin CD81 via its PA domain, which promoted ubiquitination of cytosolic lysine residues. It also down-modulates the expression of CD83 (previously described as a cell surface marker for mature dendritic cells) on CD4 T cells. Furthermore, Rho guanine dissociation inhibitor (RhoGDI) has been identified as a potential substrate of RNF128, suggesting a role for Rho effector molecules in T cell anergy. In addition, RNF128 plays a role in environmental stress responses. It promotes environmental salinity tolerance in euryhaline tilapia. RNF133 is a testis-specific endoplasmic reticulum-associated E3 ubiquitin ligase that is mainly present in the cytoplasm of elongated spermatids. It may play a role in sperm maturation through an ER-associated degradation (ERAD) pathway. RNF148 is a testis-specific E3 ubiquitin ligase that is abundantly expressed in testes and slightly expressed in pancreas. Its expression is regulated by histone deacetylases.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16802    3 CAVCIEPYKPNDVVRILTCNHLFHKNCIDPWLLEHRTCPMCK 44

RING finger, H2 subclass, found in RING finger protein 167 (RNF167) and similar proteins; RNF167, also known as RING105, is an endosomal/lysosomal E3 ubiquitin-protein ligase involved in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) ubiquitination. It ubiquitinates AMPA-type glutamate receptor subunit GluA2 and regulates its surface expression, and thus acts as a selective regulator of AMPAR-mediated neurotransmission. It acts as an endosomal membrane protein which ubiquitylates vesicle-associated membrane protein 3 (VAMP3) and regulates endosomal trafficking. Moreover, RNF167 plays a role in the regulation of TSSC5 (tumor-suppressing subchromosomal transferable fragment cDNA, also known as ORCTL2/IMPT1/BWR1A/SLC22A1L), which can function in concert with the ubiquitin-conjugating enzyme UbcH6. RNF167 is widely conserved in metazoans and contains an N-terminal signal peptide, a protease-associated (PA) domain, two transmembrane domains (TM1 and TM2), and a C-terminal C3H2C3-type RING-H2 finger domain followed by a putative PEST sequence.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWL-ELHDTCPVCRK 271
Cdd:cd16797    3 CAICLDEYEEGDKLRVLPCSHAYHSKCVDPWLtQTKKTCPVCKQ 46

RING finger, H2 subclass, found in RING finger proteins RNF111, RNF165, and similar proteins; The family includes RING finger proteins RNF111, RNF165, and similar proteins. RNF111, also known as Arkadia, is a nuclear E3 ubiquitin-protein ligase that targets intracellular effectors and modulators of transforming growth factor beta (TGF-beta)/Nodal-related signaling for polyubiquitination and proteasome-dependent degradation. It also interacts with the clathrin-adaptor 2 (AP2) complex and regulates endocytosis of certain cell surface receptors, leading to modulation of epidermal growth factor (EGF) and possibly other signaling pathways. The N-terminal half of RNF111 harbors three SUMO-interacting motifs (SIMs). It thus functions as a SUMO-targeted ubiquitin ligase (STUbL) that directly links nonproteolytic ubiquitylation and SUMOylation in the DNA damage response, as well as triggers degradation of signal-induced polysumoylated proteins, such as the promyelocytic leukemia protein (PML). RNF165, also known as Arkadia-like 2, Arkadia2, or Ark2C, is an E3 ubiquitin ligase with homology to the C-terminal half of RNF111. It is expressed specifically in the nervous system, and can serve to amplify neuronal responses to specific signals. It acts as a positive regulator of bone morphogenetic protein (BMP)-Smad signaling that is involved in motor neuron (MN) axon elongation. Both RNF165 and RNF111 contain a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16474    3 CTICLSDFEEGEDVRRLPCMHLFHQECVDQWLSTNKRCPICR 44

RING finger, H2 subclass, found in RING finger protein 122 (RNF122) and similar proteins; RNF122 is a RING finger protein associated with HEK 293T cell viability. It is localized to the endoplasmic reticulum (ER) and the Golgi apparatus, and overexpressed in anaplastic thyroid cancer cells. RNF122 functions as an E3 ubiquitin ligase that can ubiquitinate itself and undergo degradation through its RING finger in a proteasome-dependent manner. It interacts with calcium-modulating cyclophilin ligand (CAML), which is not a substrate, but a stabilizer of RNF122. RNF122 contains an N-terminal transmembrane domain and a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd16676    3 CAVCLEDFKTKDELGVLPCQHAFHRKCLVKWLEIRCVCPMCNKPI 47

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 170172564 228 ECPVCKEDYTVEEKvrqLPCNHFFHSSCIVPWLELHDTCPVCRKSLNGED 277
Cdd:cd16561    4 ECSICLEDLNDPVK---LPCDHVFCEECIRQWLPGQMSCPLCRTELPDDF 50

RING finger, H2 subclass, found in autocrine motility factor receptor (AMFR) and similar proteins; AMFR, also known as AMF receptor, or RING finger protein 45, or ER-protein gp78, is an internalizing cell surface glycoprotein localized in both plasma membrane caveolae and the endoplasmic reticulum (ER). It is involved in the regulation of cellular adhesion, proliferation, motility and apoptosis, as well as in the process of learning and memory. AMFR also functions as a RING finger-dependent ubiquitin protein ligase (E3) implicated in the degradation from the ER. AMFR contains an N-terminal RING-H2 finger and a C-terminal ubiquitin-associated (UBA)-like CUE domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 170172564 228 ECPVCKEDYtveEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd16455    2 DCAICWESM---QSARKLPCGHLFHNSCLRSWLEQDTSCPTCRMSL 44

Modified RING finger, H2 subclass (C3H2C2D-type), found in zinc finger SWIM domain-containing protein 2 (ZSWIM2) and similar proteins; ZSWIM2, also known as MEKK1-related protein X (MEX) or ZZ-type zinc finger-containing protein 2, is a testis-specific E3 ubiquitin ligase that promotes death receptor-induced apoptosis through Fas, death receptor (DR) 3 and DR4 signaling. ZSWIM2 is self-ubiquitinated and targeted for degradation through the proteasome pathway. It acts as an E3 ubiquitin ligase, through the E2, Ub-conjugating enzymes UbcH5a, UbcH5c, or UbcH6. ZSWIM2 contains four putative zinc-binding domains including an N-terminal SWIM (SWI2/SNF2 and MuDR) domain critical for its ubiquitination, and two modified RING-H2 fingers separated by a ZZ zinc finger domain, which was required for interaction with UbcH5a and its self-association. This model corresponds to the second RING-H2 finger, which is not a canonical C3H2C3-type, but a modified C3H2C2D-type.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWL-ELHDTCPVCRKSLN 274
Cdd:cd16486    1 QCRICLKAFQLGQHVRTLPCRHKFHRDCIDNWLlHSRNSCPIDGQVVY 48

RING finger, H2 subclass, found in Arabidopsis thaliana NEP1-interacting protein-like 1 (NIPL1) and similar proteins; This subfamily includes Arabidopsis thaliana NIPL1 and MISFOLDED PROTEIN SENSING RING E3 LIGASE 1 (MPSR1). NIPL1, also called RING-H2 finger protein ATL27, may be involved in the early steps of the plant defense signaling pathway. MPSR1 is a cytoplasmic E3 ubiquitin-protein ligase involved in protein quality control (PQC) under proteotoxic stress. It is essential for plant survival under proteotoxic stress. It functions by removing damaged proteins before they form cytotoxic aggregates. It recognizes misfolded proteins selectively and tethers polyubiquitin chains to the proteins directly for subsequent degradation by the 26S proteasome pathway. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 170172564 228 ECPVCKEDYTVEEKVRQLP-CNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd23119    1 CCTICLQDLQVGEIARSLPhCHHTFHLGCVDKWLGRHGSCPVCR 44

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 170172564 226 GLECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELH-DTCPVCRKSL 273
Cdd:COG5540  323 GVECAICMSNFIKNDRLRVLPCDHRFHVGCVDKWLLGYsNKCPVCRTAI 371

RING finger, H2 subclass, found in RING finger protein 215 (RNF215) and similar proteins; This family includes uncharacterized protein RNF215 and similar proteins. Although its biological function remains unclear, RNF215 shares high sequence similarity with PA-TM-RING ubiquitin ligases, which have been characterized by containing an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSLNGE 276
Cdd:cd16670    3 CAVCLDQFYKNQCLRVLPCLHEFHRDCVDPWLLLQQTCPLCKRNILGN 50

RING finger, H2 subclass, found in RING finger protein 150 (RNF150) and similar proteins; RNF150 is a RING finger protein and its polymorphisms may be associated with chronic obstructive pulmonary disease (COPD) risk in the Chinese population. Further studies with larger numbers of participants worldwide are needed for validation of the relationships between RNF150 genetic variants and the pathogenesis of COPD. RNF150 contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C-terminal C3H2C3-type RING-H2 finger domain followed by a putative PEST sequence.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd16805    9 CAVCIEGYKPNDVVRILPCRHLFHKSCVDPWLLDHRTCPMCKMNI 53

RING finger, H2 subclass, found in Arabidopsis thaliana protein ABA INSENSITIVE RING PROTEIN 1 (AIRP1) and similar proteins; This subfamily includes Arabidopsis thaliana AIRP1 and RING-H2 finger B1a (RHB1A). AIRP1, also known as RING-type E3 ubiquitin transferase AIRP1, possesses E3 ubiquitin-protein ligase activity in vitro when associated with the E2 enzyme UBC8. It plays combinatory roles with AIRP2 in the positive regulation of the abscisic acid-mediated drought stress response. RHB1A is a probable E3 ubiquitin-protein ligase. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd23116    4 VCPTCLEGYTEENPKLLTKCGHHFHLACIYEWMERSERCPVCDKEM 49

RING finger, H2 subclass, found in RING finger protein 13 (RNF13) and similar proteins; RNF13 is a widely expressed membrane-associated E3 ubiquitin-protein ligase that is functionally significant in the regulation of cancer development, muscle cell growth, and neuronal development. Its expression is developmentally regulated during myogenesis and is upregulated in various tumors. RNF13 negatively regulates cell proliferation through its E3 ligase activity. It functions as an important regulator of inositol-requiring transmembrane kinase/endonuclease IRE1alpha, mediating endoplasmic reticulum (ER) stress-induced apoptosis through the activation of the IRE1alpha-TRAF2-JNK signaling pathway. Moreover, RNF13 is involved in the regulation of the soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) complex via the ubiquitination of snapin, a SNAP25-interacting protein, which thereby controls synaptic function. In addition, RNF13 participates in regulating the function of satellite cells by modulating cytokine composition. RNF13 is evolutionarily conserved among many metazoans and contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C-terminal C3H2C3-type RING-H2 finger domain followed by a putative PEST sequence.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWL-ELHDTCPVCRKSL 273
Cdd:cd16796   11 CAICLDEYEEGDKLRILPCSHAYHCKCVDPWLtKTKKTCPVCKQKV 56

RING finger, H2 subclass, found in zinc/RING finger protein 3 (ZNRF3) and similar proteins; ZNRF3, also known as RING finger protein 203 (RNF203), is a homolog of Ring finger protein 43 (RNF43). It is a transmembrane E3 ubiquitin-protein ligase that is associated with the Wnt receptor complex, and negatively regulates Wnt signaling by promoting the turnover of frizzled and lipoprotein receptor-related protein LRP6 in an R-spondin-sensitive manner. It inhibits gastric cancer cell growth and promotes cell apoptosis by affecting the Wnt/beta-catenin/TCF signaling pathway. ZNRF3 contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C3H2C3-type RING-H2 finger followed by a long C-terminal region.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16799    1 DCAICLEKYIDGEELRVIPCTHRFHKKCVDPWLLQHHTCPHCR 43

HRD ubiquitin ligase complex, ER membrane component [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 170172564 213 LPTVTVTQEQVNTGLeCPVCKEDY----------TVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSLNGEDSTRQT 282
Cdd:COG5243  275 YPTATEEQLTNSDRT-CTICMDEMfhpdheplprGLDMTPKRLPCGHILHLHCLKNWLERQQTCPICRRPVIFDQSSPTP 353

                 ....*...
gi 170172564 283 QSSEASAS 290
Cdd:COG5243  354 ASPNVRNT 361

RING finger, H2 subclass, found in RING finger proteins RNF139, RNF145, and similar proteins; RNF139, also known as translocation in renal carcinoma on chromosome 8 protein (TRC8), is an endoplasmic reticulum (ER)-resident multi-transmembrane protein that functions as a potent growth suppressor in mammalian cells, inducing G2/M arrest, decreased DNA synthesis and increased apoptosis. It is a tumor suppressor that has been implicated in a novel regulatory relationship linking the cholesterol/lipid biosynthetic pathway with cellular growth control. A mutation in RNF139 has been identified in families with hereditary renal (RCC) and thyroid cancers. RNF145 is an uncharacterized RING finger protein encoded by the RNF145 gene, which is expressed in T lymphocytes, and its expression is altered in acute myelomonocytic and acute promyelocytic leukemias. Although its biological function remains unclear, RNF145 shows high sequence similarity with RNF139. Both RNF139 and RNF145 contain a C3H2C3-type RING-H2 finger with possible E3-ubiquitin ligase activity.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 170172564 229 CPVCKEDYTveeKVRQLPCNHFFHSSCIVPWLELHDTCPVC 269
Cdd:cd16476    3 CAICYQEMK---EARITPCNHFFHGLCLRKWLYVQDTCPLC 40

RING finger, H2 subclass, found in Saccharomyces cerevisiae transmembrane E3 ubiquitin-protein ligase 1 (TUL1) and similar proteins; This subfamily includes Saccharomyces cerevisiae TUL1, Schizosaccharomyces pombe DSC E3 ubiquitin ligase complex subunit 1 (DSC1), and Arabidopsis thaliana protein FLYING SAUCER 2 (FLY2). TUL1 is the catalytic component of DSC E3 ubiquitin ligase complexes that tag proteins present in Golgi, endosome and vacuole membranes and function in protein homeostasis under non-stress conditions, and support a role in protein quality control. It mediates ubiquitination of vacuolar proteins such as CPS1, PPN1, PEP12 and other proteins containing exposed hydrophilic residues within their transmembrane domains, leading to their sorting into internal vesicles in late endosomes. TUL1 also targets the unpalmitoylated endosomal SNARE TLG1 to the multivesicular body (MVB) pathway. DSC1, also known as defective for SREBP cleavage protein 1, is the catalytic component of the DSC E3 ubiquitin ligase complex required for the sre1 transcriptional activator proteolytic cleavage to release the soluble transcription factor from the membrane in low oxygen or sterol conditions. FLY2 acts as an E3 ubiquitin-protein ligase that may be involved in xylem development. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 170172564 228 ECPVCKE--DYTVEEKVRQ----LPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd23117    6 DCVICMSdiELPSTNSVRRdymvTPCNHIFHTNCLERWMDIKLECPTCRRPL 57

RING finger, H2 subclass, found in RING finger protein 43 (RNF43) and similar proteins; RNF43 is a transmembrane E3 ubiquitin-protein ligase that plays an important role in frizzled (FZD)-dependent regulation of the Wnt/beta-catenin pathway. It functions as a tumor suppressor that inhibits Wnt/beta-catenin signaling by ubiquitinating FZD receptor and targeting it to the lysosomal pathway for degradation. miR-550a-5p directly targeted the 3'-UTR of gene RNF43 and regulated its expression. Moreover, RNF43 interacts with NEDD-4-like ubiquitin-protein ligase-1 (NEDL1) and regulates p53-mediated transcription. It may also be involved in cell growth control through the interaction with HAP95, a chromatin-associated protein interfacing the nuclear envelope. Mutations of RNF43 have been identified in various tumors, including colorectal cancer (CRC), endometrial cancer, mucinous ovarian tumors, gastric adenocarcinoma, pancreatic ductal adenocarcinoma, liver fluke-associated cholangiocarcinoma, hepatocellular carcinoma, and glioma. RNF43 contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C3H2C3-type RING-H2 finger followed by a long C-terminal region.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVC 269
Cdd:cd16798    6 CAICLEEFSEGQELRIISCSHEFHRECVDPWLHQHRTCPLC 46

RING finger, H2 subclass, found in Arabidopsis thaliana MED25-binding RING-H2 protein (MBR) and similar proteins; This subfamily includes MBR1 and MBR2 (also called HAL3-interacting protein 1 or AtHIP1). They are E3 ubiquitin-protein ligases that function as regulators of MED25 stability by targeting MED25 for degradation in a RING-H2-dependent manner. Proteasome-dependent degradation of MED25 seems to activate its function as a positive regulator of FLOWERING LOCUS T (FT) and is important to induce the expression of FT, and consequently to promote flowering. MBR2 may also function downstream of HAL3 and be required for HAL3-regulated plant growth. Activation of MBR2 by HAL3 may lead to the degradation of cell cycle suppressors, resulting in enhancement of cell division and plant growth. Both MBR1 and MBR2 contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd23113    5 CCICQEEYEEGDELGTIECGHEYHSDCIKQWLVQKNLCPICK 46

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 170172564 226 GLECPVCKEDYTV--EEKVRQLPCNHFFHSSCIVPWL-ELHDTCPVCRKS 272
Cdd:cd16450    2 GNTCPICFEPWTSsgEHRLVSLKCGHLFGYSCIEKWLkGKGKKCPQCNKK 51

Modified RING-CH finger, H2 subclass (C4HC2H-type), found in the ZNRF family; The ZNRF family includes zinc/RING finger proteins ZNRF1, ZNRF2, and similar proteins. It has been characterized by containing a unique combination of zinc finger-RING finger motifs in the C-terminal region, which is evolutionarily conserved in a wide range of species, including Caenorhabditis elegans and Drosophila. ZNRF proteins function as E3 ubiquitin ligases and are highly expressed in central nervous system (CNS) and peripheral nervous system (PNS) neurons, particularly during development and in adulthood. ZNRF1 and ZNRF2 are differentially localized within the synaptic region. ZNRF1 is associated with synaptic vesicle membranes, whereas ZNRF2 is present in presynaptic plasma membranes. They are N-myrisotoylated and also located in the endosome-lysosome compartment in fibroblasts. ZNRF proteins may play a role in the establishment and maintenance of neuronal transmission and plasticity via their ubiquitin ligase activity, as well as in regulating Ca2+-dependent exocytosis. The RING fingers found in ZNRF proteins are modified as C4HC2H-type RING-CH finger, rather than the typical C4HC3-type RING-CH finger, which is a variant of the RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCPV 268
Cdd:cd16489    1 ECVICLEELEAGDTIARLPCLCIYHKKCIDDWFEVNRSCPE 41

RING finger, H2 subclass, found in RING finger proteins RNF121, RNF175 and similar proteins; This subfamily includes RNF121, RNF175 and similar proteins. RNF121 is an E3-ubiquitin ligase present in the endoplasmic reticulum (ER) and cis-Golgi compartments. It is a novel regulator of apoptosis. It also facilitates the degradation and membrane localization of voltage-gated sodium (NaV) channels, and thus plays a role in the quality control of NaV channels during their synthesis and subsequent transport to the membrane. Moreover, RNF121 acts as a broad regulator of nuclear factor kappaB (NF-kappaB) signaling since its silencing also dampens NF-kappaB activation following stimulation of toll-like receptors (TLRs), nod-like receptors (NLRs), RIG-I-like Receptors (RLRs) or after DNA damage. RNF121 contains five conserved transmembrane (TM) domains and a C3H2C2-type RING-H2 finger. RNF175 is an uncharacterized RING finger protein that shows high sequence similarity with RNF121. This family also includes Arabidopsis RING finger E3 ligase RHA2A, RHA2B, and their homologs. RHA2A is a positive regulator of abscisic acid (ABA) signaling during seed germination and early seedling development. RHA2B may play a role in the ubiquitin-dependent proteolysis pathway that respond to proteasome inhibition. All subfamily members contain a C3H2C3-type RING-H2 finger, which is responsible for E3-ubiquitin ligase activity.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 170172564 226 GLECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLEL--HDTCPVCRK 271
Cdd:cd16475    7 GQKLDVDDNEEGIIEKTYKLSCNHVFHEFCIRGWCIVgkKQTCPYCKE 54

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 170172564 229 CPVCKEDYTveeKVRQLPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16532    3 CPICQDEFK---DPVVLRCKHIFCEDCVSEWFERERTCPLCR 41

RING finger, H2 subclass, found in RING finger protein 145 (RNF145) and similar proteins; RNF145 is an uncharacterized RING finger protein encoded by the RNF145 gene, which is expressed in T lymphocytes, and its expression is altered in acute myelomonocytic and acute promyelocytic leukemias. Although its biological function remains unclear, RNF145 shows high sequence similarity with RNF139, an endoplasmic reticulum (ER)-resident multi-transmembrane protein that functions as a potent growth suppressor in mammalian cells, inducing G2/M arrest, decreased DNA synthesis and increased apoptosis. Like RNF139, RNF145 contains a C3H2C3-type RING-H2 finger with possible E3-ubiquitin ligase activity.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 170172564 229 CPVCKEDYtveEKVRQLPCNHFFHSSCIVPWLELHDTCPVC 269
Cdd:cd16684    5 CSICYQDM---KSAVITPCSHFFHAGCLKKWLYVQETCPLC 42

Modified RING-CH finger, H2 subclass (C4HC2H-type), found in zinc/RING finger protein 1 (ZNRF1) and similar proteins; ZNRF1, also known as Nerve injury-induced gene 283 protein (nin283), or peripheral nerve injury protein (PNIP), is an E3 ubiquitin-protein ligase that is highly expressed in the nervous system during development and is associated with synaptic vesicle membranes. It is N-myrisotoylated and is also located in the endosome-lysosome compartment in fibroblasts, suggesting it may participate in ubiquitin-mediated protein modification. It contains an N-terminal MAGE domain, and a special C-terminal domain that combines a zinc finger and a modified C4HC2H-type RING-CH finger, rather than the typical C4HC3-type RING-CH finger, which is a variant of the RING-H2 finger. Only the RING finger of the zinc finger-RING finger motif is required for its E3 ubiquitin ligase activity. ZNRF1 regulates Schwann cell differentiation by proteasomal degradation of glutamine synthetase (GS). It also mediates regulation of neuritogenesis via interaction with beta-tubulin type 2 (Tubb2). Moreover, ZNRF1 promotes Wallerian degeneration by degrading AKT to induce glycogen synthase kinase-3beta (GSK3B)-dependent CRMP2 phosphorylation. Furthermore, ZNRF1 and its sister protein ZNRF2 regulate the ubiquitous Na+/K+ pump (Na+/K+ATPase). In addition, ZNRF1 may be associated with leukemogenesis of acute lymphoblastic leukemia (ALL) with paired box domain gene 5 (PAX5) alteration.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCP 267
Cdd:cd16694    1 ECVICLEELLQGDTIARLPCLCIYHKSCIDSWFEVNRSCP 40

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
                 ....*....|....*....|....*.
gi 170172564 245 LPCNHFFHSSCIVPWLELHDTCPVCR 270
Cdd:cd16545   15 LPCAHSYCQKCIDKWSDRHRTCPICR 40

RING finger, H2 subclass, found in 43 kDa receptor-associated protein of the synapse (Rapsyn) and similar proteins; Rapsyn, also known as acetylcholine receptor (AChR)-associated 43 kDa protein or RING finger protein 205 (RNF205), is a 43 kDa postsynaptic protein that plays an essential role in the clustering and maintenance of AChR in the postsynaptic membrane of the motor endplate. AChRs enable the transport of rapsyn from the Golgi complex to the plasma membrane through a molecule-specific interaction. Rapsyn also mediates subsynaptic anchoring of protein kinase A (PKA) type I in close proximity to the postsynaptic membrane, which is essential for synapse maintenance. Its mutations in humans cause endplate AChR deficiency and myasthenic syndrome. Rapsyn contains an N-terminal myristoylation signal required for membrane association, seven tetratricopeptide repeats (TPRs) that subserve rapsyn self-association, a coiled-coil domain responsible for the binding of determinants within the long cytoplasmic loop of each AChR subunit, a C3H2C3-type RING-H2 finger that binds to the cytoplasmic domain of beta-dystroglycan and to S-NRAP and links rapsyn to the subsynaptic cytoskeleton, and a serine phosphorylation site.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 170172564 226 GLECPVCKEDYT-VEEKVRQLPCNHFFHSSCIVPWLELHD-TCPVCRK 271
Cdd:cd16478    1 ELFCGMCGESIGeKNEQLQALPCSHIFHLKCLQTNLRGGTrGCPNCRR 48

RING finger, H2 subclass, found in Saccharomyces cerevisiae RING-H2 zinc finger protein RHA2B and similar proteins; RHA2B is an E3 ubiquitin-protein ligase involved in the positive regulation of abscisic acid (ABA) signaling and responses to salt and osmotic stresses during seed germination and early seedling development. It acts additively with RHA2A in regulating ABA signaling and drought response. RHA2B contains a C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLE-LHDTCPVCR 270
Cdd:cd23123    3 CCICLDKLKTGEEVKKLDCRHKFHKQCIEGWLKhLNFNCPLCR 45

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 170172564 228 ECPVCKEDytVEEKVRQLPCNHFFHSSCIVPWLELHDTCPVCRKSL 273
Cdd:cd23130    2 VCPICLDD--PEDEAITLPCLHQFCYTCILRWLQTSPTCPLCKTPV 45

first RING finger, H2 subclass, found in RING finger protein 32 (RNF32) and similar proteins; RNF32 is mainly expressed in testis spermatogenesis, most likely in spermatocytes and/or in spermatids, suggesting a possible role in sperm formation. RNF32 contains two C3H2C3-type RING-H2 fingers separated by an IQ domain of unknown function. Although the biological function of RNF32 remains unclear, proteins with double RING-H2 fingers may act as scaffolds for binding several proteins that function in the same pathway. This model corresponds to the first RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 170172564 229 CPVCKEDYTVEEKVrQLPCNHFFHSSCIVPWLEL--HDTCPVCRKS 272
Cdd:cd16677    2 CPICLEDFGLQQQV-LLSCSHVFHRACLESFERFsgKKTCPMCRKE 46

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 170172564  228 ECPVCkedYTVEEKV-RQLP------CNHFFHSSCIVPWLEL--HDTCPVCRKSL 273
Cdd:COG5219  1471 ECAIC---YSVLDMVdRSLPskrcatCKNKFHTRCLYKWFASsaRSNCPLCRSEI 1522

RING finger, HC subclass, found in RING finger protein 4 (RNF4) and similar proteins; RNF4, also known as small nuclear ring finger protein (SNURF), is a SUMO-targeted E3 ubiquitin-protein ligase with a pivotal function in the DNA damage response (DDR) by interacting with the deubiquitinating enzyme ubiquitin-specific protease 11 (USP11), a known DDR-component, and further facilitating DNA repair. It plays a novel role in preventing the loss of intact chromosomes and ensures the maintenance of chromosome integrity. Moreover, RNF4 is responsible for the UbcH5A-catalyzed formation of K48 chains that target SUMO-modified promyelocytic leukemia (PML) protein for proteasomal degradation in response to arsenic treatment. It also interacts with telomeric repeat binding factor 2 (TRF2) in a small ubiquitin-like modifier (SUMO)-dependent manner and preferentially targets SUMO-conjugated TRF2 for ubiquitination through SUMO-interacting motifs (SIMs). Furthermore, RNF4 can form a complex with a Ubc13-ubiquitin conjugate and Ube2V2. It catalyzes K63-linked polyubiquitination by the Ube2V2-Ubc13 (ubiquitin-loaded) complex. Meanwhile, RNF4 negatively regulates nuclear factor kappa B (NF-kappaB) signaling by down-regulating transforming growth factor beta (TGF-beta)-activated kinase 1 (TAK1)-TAK1-binding protein2 (TAB2). RNF4 contains four SIMs followed by a C3HC4-type RING-HC finger at the C-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 170172564 227 LECPVCKEDYTVEEKVRQL----PCNHFFHSSCIVPWLELHDTCPVCRKSLN 274
Cdd:cd16533    4 VSCPICMDGYSEIVQSGRLivstECGHVFCSQCLRDSLKNANTCPTCRKKLN 55

zinc-RING finger domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 170172564  228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPwLELHDTCPVCRK 271
Cdd:pfam14634   1 HCNKCFKELSKTRPFYLTSCGHIFCEECLTR-LLQERQCPICKK 43

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
                 ....*....|....*....|....*....|....*....|..
gi 170172564 229 CPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHD-TCPVC 269
Cdd:cd00162    1 CPICREEMNDRRPVVLLSCGHTFSRSAIARWLEGSKqKCPFC 42

RING-CH finger, H2 subclass (C4HC3-type), found in E3 ubiquitin-protein ligase listerin and similar proteins; Listerin, also known as RING finger protein 160 or zinc finger protein 294, is the mammalian homolog of yeast Ltn1. It is widely expressed in all tissues, but motor and sensory neurons and neuronal processes in the brainstem and spinal cord are primarily affected in the mutant. Listerin is required for embryonic development and plays an important role in neurodegeneration. It also functions as a critical E3 ligase involving quality control of nonstop proteins. It mediates ubiquitylation of aberrant proteins that become stalled on ribosomes during translation. Ltn1 works with several cofactors to form a large ribosomal subunit-associated quality control complex (RQC), which mediates the ubiquitylation and extraction of ribosome-stalled nascent polypeptide chains for proteasomal degradation. It appears to first associate with nascent chain-stalled 60S subunits together with two proteins of unknown function, Tae2 and Rqc1. Listerin contains a long stretch of HEAT (Huntingtin, Elongation factor 3, PR65/A subunit of protein phosphatase 2A, and TOR) or ARM (Armadillo) repeats in the N terminus and middle region, and a catalytic RING-CH finger, also known as vRING or RINGv, with an unusual arrangement of zinc-coordinating residues in the C-terminus . Its cysteines and histidines are arranged in the sequence as C4HC3-type, rather than the C3H2C3-type in canonical RING-H2 finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 170172564 228 ECPVCkedYTV-EEKVRQLP------CNHFFHSSCIVPWLE--LHDTCPVCR 270
Cdd:cd16491    2 ECPIC---YSViHGSNHSLPklkcktCKNKFHSACLYKWFRssNKSTCPLCR 50

Modified RING-CH finger, H2 subclass (C4HC2H-type), found in zinc/RING finger protein 2 (ZNRF2) and similar proteins; ZNRF2, also known as protein Ells2 or RING finger protein 202 (RNF202), is an E3 ubiquitin-protein ligase that is highly expressed in the nervous system during development and is present in presynaptic plasma membranes. It is N-myrisotoylated and is also located in the endosome-lysosome compartment in fibroblasts. It contains an N-terminal MAGE domain, and a special C-terminal domain that combines a zinc finger and a modified C4HC2H-type RING-CH finger, rather than the typical C4HC3-type RING-CH finger, which is a variant of RING-H2 finger. Only the RING finger of the zinc finger-RING finger motif is required for its E3 ubiquitin ligase activity. Together with its sister protein ZNRF1, ZNRF2 regulates the ubiquitous Na+/K+ pump (Na+/K+ATPase).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 170172564 228 ECPVCKEDYTVEEKVRQLPCNHFFHSSCIVPWLELHDTCP 267
Cdd:cd16695   12 ECAICLEELQQGDTIARLPCLCIYHKGCIDEWFEVNRSCP 51

RING finger, HC subclass, found in RING finger protein 186 (RNF186) and similar proteins; RNF186 is an E3 ubiquitin-protein ligase with an N-terminal C3HC4-type RING-HC finger and two putative C-terminal transmembrane domains which enable it to localize in a certain organelle. It regulates RING-dependent self-ubiquitination, as well as endoplasmic reticulum (ER) stress-mediated apoptosis through interaction with the Bcl-2 family protein BNip1.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 170172564 227 LECPVCKEDYTVE-EKVRQLPCNHFFHSSCIVPWLELHD-----TCPVCRK 271
Cdd:cd16557    2 LECLVCRNPYSCFvRKPKLLACQHAFCAICLKLILCEQDgtwsvTCPLCRR 52