modified RING finger, H2 subclass (C3H2C2D-type), found in RING-box protein 1 (RBX1) and similar proteins; RBX1, also known as Hrt1, protein ZYP, RING finger protein 75 (RNF75), or regulator of cullins 1 (ROC1), is an E3 ubiquitin-protein ligase necessary for ubiquitin ligation activity of multimeric cullin (Cul)-RING E3 ligases (CRLs). RBX1-containing CRLs are involved in the NEDD8 pathway; RBX1 specifically regulates NEDD8ylation of Cul1-4. It can also bind and activate HIV-1 Vif-Cullin5 E3 ligase complex in vitro. Moreover, RBX1 is an essential element of Skp1/Cullin/F-box (SCF) E3-ubiquitin ligase complexes that target diverse proteins for proteasome-mediated degradation. It is a direct functional target of miR-194 and plays an important role in proliferation and migration of gastric cancer (GC) cells. RBX1 is also an essential component of KEAP1/CUL3/RBX1 E3-ubiquitin ligase complex that functions as a regulator of NFE2-related factor 2 (NRF2) and plays a key role in NRF2 pathway deregulation in multiple tumor types, including ovarian carcinomas (OVCA) and papillary thyroid carcinoma (PTC). Furthermore, RBX1 associates with DDB1, Cul4A, and Fbxw5 to form the Fbxw5-DDB1-Cul4A-Rbx1 complex that may function as a dual SUMO/ubiquitin ligase suppressing c-Myb activity through sumoylation or ubiquitination. RBX1 contains a C-terminal modified RING-H2 finger that is of C3H2C2D-type, rather than the canonical C3H2C3-type. The modified RING-H2 finger is essential for its ligase activity.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 238880666  54 ENCAICRNHLMEPCIECQPNaMGNIPSEECIPAWGVCNHAFHLHCIRRWLKTRNACPLDSTNW 116
Cdd:cd16485    1 DNCAICRNHIMDLCIECQAN-QASATSEECTVAWGVCNHAFHFHCISRWLKTRQVCPLDNREW 62

N1R/p28-like protein; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 238880666  54 ENCAICrnhlMEPCIECQPNAM--GNIPSeecipawgvCNHAFHLHCIRRWLKTRNACPL 111
Cdd:PHA02929 175 KECAIC----MEKVYDKEIKNMyfGILSN---------CNHVFCIECIDIWKKEKNTCPV 221

modified RING finger, H2 subclass (C3H2C2D-type), found in RING-box protein 1 (RBX1) and similar proteins; RBX1, also known as Hrt1, protein ZYP, RING finger protein 75 (RNF75), or regulator of cullins 1 (ROC1), is an E3 ubiquitin-protein ligase necessary for ubiquitin ligation activity of multimeric cullin (Cul)-RING E3 ligases (CRLs). RBX1-containing CRLs are involved in the NEDD8 pathway; RBX1 specifically regulates NEDD8ylation of Cul1-4. It can also bind and activate HIV-1 Vif-Cullin5 E3 ligase complex in vitro. Moreover, RBX1 is an essential element of Skp1/Cullin/F-box (SCF) E3-ubiquitin ligase complexes that target diverse proteins for proteasome-mediated degradation. It is a direct functional target of miR-194 and plays an important role in proliferation and migration of gastric cancer (GC) cells. RBX1 is also an essential component of KEAP1/CUL3/RBX1 E3-ubiquitin ligase complex that functions as a regulator of NFE2-related factor 2 (NRF2) and plays a key role in NRF2 pathway deregulation in multiple tumor types, including ovarian carcinomas (OVCA) and papillary thyroid carcinoma (PTC). Furthermore, RBX1 associates with DDB1, Cul4A, and Fbxw5 to form the Fbxw5-DDB1-Cul4A-Rbx1 complex that may function as a dual SUMO/ubiquitin ligase suppressing c-Myb activity through sumoylation or ubiquitination. RBX1 contains a C-terminal modified RING-H2 finger that is of C3H2C2D-type, rather than the canonical C3H2C3-type. The modified RING-H2 finger is essential for its ligase activity.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 238880666  54 ENCAICRNHLMEPCIECQPNaMGNIPSEECIPAWGVCNHAFHLHCIRRWLKTRNACPLDSTNW 116
Cdd:cd16485    1 DNCAICRNHIMDLCIECQAN-QASATSEECTVAWGVCNHAFHFHCISRWLKTRQVCPLDNREW 62

Anaphase-promoting complex subunit 11 RING-H2 finger; Apc11 is one of the subunits of the anaphase-promoting complex or cyclosome. The APC subunits are cullin family proteins with ubiquitin ligase activity. Polyubiquitination marks proteins for degradation by the 26S proteasome and is carried out by a cascade of enzymes that includes ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s). Apc11 acts as an E3 enzyme and is responsible for recruiting E2s to the APC and for mediating the subsequent transfer of ubiquitin to APC substrates in vivo. In Saccharomyces cerevisiae this RING-H2 finger protein defines the minimal ubiquitin ligase activity of the APC, and the integrity of the RING-H2 finger is essential for budding yeast cell viability.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 238880666   37 EVKKWTAVAFWSWDM-QIENCAICRNHLMEPCIECQpnamgnIPSEECIPAWGVCNHAFHLHCIRRWLKTRNA---CPLD 112
Cdd:pfam12861   4 KIKEWNAVATWLWDVpSDDVCGICRVSFDGTCPDCK------FPGDDCPLVWGKCSHNFHMHCILKWLHTETSkglCPMC 77

                  ....*...
gi 238880666  113 STNWTYQK 120
Cdd:pfam12861  78 RQTFKFAE 85

RING finger, H2 subclass, found in RING-box protein 2 (RBX2) and similar proteins; RBX2, also known as CKII beta-binding protein 1 (CKBBP1), RING finger protein 7 (RNF7), regulator of cullins 2 (ROC2), or sensitive to apoptosis gene protein (SAG), is an E3 ubiquitin-protein ligase that protects cells from apoptosis, confers radioresistance, and plays an essential and non-redundant role in embryogenesis and vasculogenesis. It promotes ubiquitination and degradation of a number of protein substrates, including c-JUN, DEPTOR, HIF-1alpha, IkappaBalpha, NF1, NOXA, p27, and procaspase-3, thus regulating various signaling pathways and biological processes. RBX2 is necessary for ubiquitin ligation activity of the multimeric cullin (Cul)-RING E3 ligases (CRLs). RBX2-containing CRLs are involved in the NEDD8 pathway and RBX2 specifically regulates NEDD8ylation of Cul5. It can bind and activate the HIV-1 Vif-Cullin5 E3 ligase complex in vitro. It is also a substrate of NEDD4-1 E3 ubiquitin ligase and mediates NEDD4-1 induced chemosensitization. The inactivation of RBX2 E3 ubiquitin ligase activity triggers senescence and inhibits Kras-induced immortalization. Endothelial deletion of RBX2 causes embryonic lethality and blocks tumor angiogenesis, and may have potential use in anti-angiogenesis therapy of human cancers. Moreover, as a component of the Cullin 5-RING E3 ubiquitin ligase (CRL5) complex, RBX2 regulates neuronal migration through different CRL5 adaptors, such as SOCS7. RBX2 also functions as a redox inducible antioxidant protein that scavenges oxygen radicals by forming inter- and intra-molecular disulfide bonds when acting alone. It contains a C-terminal C3H2C3-type RING-H2 finger that is essential for its ligase activity.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 238880666  56 CAICRNHLMEPCIECQpnamGNIPSEECIPAWGVCNHAFHLHCIRRWLKTRNACPLDSTNW 116
Cdd:cd16466    4 CAICRVQVMDACLRCQ----AENKQEDCVVVWGECNHSFHNCCMSLWVKQNNRCPLCQQDW 60

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
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd16469   21 CGHAFHTKCLKKWLEVRNSCPI 42

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 238880666  56 CAICRNHLMEPCiecqpnamgNIpseecipAWGVCNHAFHLHCIRRWLKTRNA-CPL 111
Cdd:cd16448    1 CVICLEEFEEGD---------VV-------RLLPCGHVFHLACILRWLESGNNtCPL 41

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
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd16467   20 CSHEFHSECVDRWLKENSSCPI 41

Ring finger domain;

                          10        20
                  ....*....|....*....|..
gi 238880666   90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:pfam13639  21 CGHHFHRECLDKWLRSSNTCPL 42

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

                         10        20
                 ....*....|....*....|.
gi 238880666  90 CNHAFHLHCIRRWLKTRNACP 110
Cdd:cd16481   19 CGHIFHKECIKQWLKEQSTCP 39

Modified RING finger, HC subclass (C3HC3D-type), found in PHD and RING finger domain-containing protein 1 (PHRF1) and similar proteins; PHRF1, also known as KIAA1542, or CTD-binding SR-like protein rA9, is a ubiquitin ligase which induces the ubiquitination of TGIF (TG-interacting factor) at lysine 130. It acts as a tumor suppressor that promotes the transforming growth factor (TGF)-beta cytostatic program through selective release of TGIF-driven promyelocytic leukemia protein (PML) inactivation. PHRF1 contains a plant homeodomain (PHD) finger and a modified C3HC3D-type RING-HC finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 238880666  54 ENCAICRNHLMEpciecqpnamgnipSEECIPAwgVCNHAFHLHCIRRWLKTRNACPLD 112
Cdd:cd16635    5 ESCPICLNTFRD--------------QAVGTPE--SCDHIFCLDCILEWSKNANTCPVD 47

N1R/p28-like protein; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 238880666  54 ENCAICrnhlMEPCIECQPNAM--GNIPSeecipawgvCNHAFHLHCIRRWLKTRNACPL 111
Cdd:PHA02929 175 KECAIC----MEKVYDKEIKNMyfGILSN---------CNHVFCIECIDIWKKEKNTCPV 221

RING finger, H2 subclass, found in RING finger protein 44 (RNF44) and similar proteins; RNF44 is an uncharacterized RING finger protein that shows high sequence similarity with RNF38, which is a nuclear E3 ubiquitin protein ligase that plays a role in regulating p53. RNF44 contains a coiled-coil motif, a KIL motif (Lys-X2-Ile/Leu-X2-Ile/Leu, X can be any amino acid), and a C3H2C2-type RING-H2 finger.

                         10        20
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd16680   28 CNHEFHTKCVDKWLKTNRTCPI 49

RING finger, H2 subclass, found in synoviolin and similar proteins; Synoviolin, also known as synovial apoptosis inhibitor 1 (Syvn1), Hrd1, or Der3, is an endoplasmic reticulum (ER)-anchoring E3 ubiquitin ligase that functions as a suppressor of ER stress-induced apoptosis and plays a role in homeostasis maintenance. It also targets tumor suppressor gene p53 for proteasomal degradation, suggesting crosstalk between ER associated degradation (ERAD) and p53 mediated apoptotic pathway under ER stress. Moreover, synoviolin controls body weight and mitochondrial biogenesis through negative regulation of the thermogenic coactivator peroxisome proliferator-activated receptor coactivator (PGC)-1beta. It upregulates amyloid beta production by targeting a negative regulator of gamma-secretase, Retention in endoplasmic reticulum 1 (Rer1), for degradation. It is also involved in the degradation of endogenous immature nicastrin, and affects amyloid beta-protein generation. Moreover, synoviolin is highly expressed in rheumatoid synovial cells and may be involved in the pathogenesis of rheumatoid arthritis (RA). It functions as an anti-apoptotic factor that is responsible for the outgrowth of synovial cells during the development of RA. It promotes inositol-requiring enzyme 1 (IRE1) ubiquitination and degradation in synovial fibroblasts with collagen-induced arthritis. Furthermore, the upregulation of synoviolin may represent a protective response against neurodegeneration in Parkinson's disease (PD). In addition, synoviolin is involved in liver fibrogenesis. Synoviolin contains a C3H2C2-type RING-H2 finger.

                         10        20
                 ....*....|....*....|.
gi 238880666  90 CNHAFHLHCIRRWLKTRNACP 110
Cdd:cd16479   20 CGHIFHLSCLRSWLQRQQTCP 40

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

                         10        20
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd16675   21 CKHAFHRKCLIKWLEVRKVCPL 42

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
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd23130   19 CLHQFCYTCILRWLQTSPTCPL 40

RING finger, H2 subclass, found in Arabidopsis thaliana RING-H2 finger A1a (RHA1A), A1b (RHA1B) and similar proteins; This subfamily includes Arabidopsis thaliana RHA1A, RHA1B and XERICO. RHA1A is a probable E3 ubiquitin-protein ligase that may possess E3 ubiquitin ligase activity in vitro. RHA1B possesses E3 ubiquitin-protein ligase activity when associated with the E2 enzyme UBC8 in vitro. XERICO functions on abscisic acid homeostasis at post-translational level, probably through ubiquitin/proteasome-dependent substrate-specific degradation. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30
                 ....*....|....*....|....*....|....*...
gi 238880666  80 SEECIPAWGVCNHAFHLHCIRRWLKT-RNACPLDSTNW 116
Cdd:cd23121   13 SDEKLRQLPKCGHIFHHHCLDRWIRYnKITCPLCRADL 50

RING finger, H2 subclass, found in RING finger protein 139 (RNF139) 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. RNF139 physically and functionally interacts with von Hippel-Lindau (VHL), which is part of an SCF related E3-ubiquitin ligase complex with "gatekeeper" function in renal carcinoma and is defective in most sporadic clear-cell renal cell carcinomas (ccRCC). It suppresses growth and functions with VHL in a common pathway. RNF139 also suppresses tumorigenesis by targeting heme oxygenase-1 for ubiquitination and degradation. Moreover, RNF139 is a target of Translin (TSN), a posttranscriptional regulator of genes transcribed by the transcription factor CREM-tau in postmeiotic male germ cells, suggesting a role of RNF139 in dysgerminoma. In addition, RNF139 forms an integral part of a novel multi-protein ER complex, containing MHC I, US2, and signal peptide peptidase, which is associated with the ER-associated degradation (ERAD) pathway. It is required for the ubiquitination of MHC class I molecules before dislocation from the ER. As a novel sterol-sensing ER membrane protein, RNF139 hinders sterol regulatory element-binding protein-2 (SREBP-2) processing through interaction with SREBP-2 and SREBP cleavage-activated protein (SCAP), regulating its own turnover rate via its E3 ubiquitin ligase activity. RNF139 shows two regions of similarity with the receptor for sonic hedgehog (SHH), Patched. The first region corresponds to the second extracellular domain of Patched, which is involved in binding SHH. The second region is a putative sterol-sensing domain (SSD). The C-terminal half of RNF139 contains a C3H2C3-type RING-H2 finger with E3-ubiquitin ligase activity in vitro.

                         10        20
                 ....*....|....*....|..
gi 238880666  90 CNHAFHLHCIRRWLKTRNACPL 111
Cdd:cd16683   23 CNHYFHALCLRKWLYIQDTCPM 44