Atrophin-1 family; Atrophin-1 is the protein product of the dentatorubral-pallidoluysian atrophy (DRPLA) gene. DRPLA OMIM:125370 is a progressive neurodegenerative disorder. It is caused by the expansion of a CAG repeat in the DRPLA gene on chromosome 12p. This results in an extended polyglutamine region in atrophin-1, that is thought to confer toxicity to the protein, possibly through altering its interactions with other proteins. The expansion of a CAG repeat is also the underlying defect in six other neurodegenerative disorders, including Huntington's disease. One interaction of expanded polyglutamine repeats that is thought to be pathogenic is that with the short glutamine repeat in the transcriptional coactivator CREB binding protein, CBP. This interaction draws CBP away from its usual nuclear location to the expanded polyglutamine repeat protein aggregates that are characteriztic of the polyglutamine neurodegenerative disorders. This interferes with CBP-mediated transcription and causes cytotoxicity.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017  291 SQQISNSdtPSPPPGLSKSnPVIPISSSNHSARSPFEGAvtESQSLFSDNFRHPNPIPSGLPPFPSSPQTSSDWPTAPEP 370
Cdd:pfam03154 421 SQQLPPP--PAQPPVLTQS-QSLPPPAASHPPTSGLHQV--PSQSPFPQHPFVPGGPPPITPPSGPPTSTSSAMPGIQPP 495

                          90
                  ....*....|....*
gi 300069017  371 QSLFTSETIPVSSST 385
Cdd:pfam03154 496 SSASVSSSGPVPAAV 510

RNA recognition motif (RRM) found in Eukaryotic CCR4-NOT transcription complex subunit 4 (NOT4) and similar proteins; This subfamily corresponds to the RRM of NOT4, also termed CCR4-associated factor 4, or E3 ubiquitin-protein ligase CNOT4, or potential transcriptional repressor NOT4Hp, a component of the CCR4-NOT complex, a global negative regulator of RNA polymerase II transcription. NOT4 functions as an ubiquitin-protein ligase (E3). It contains an N-terminal C4C4 type RING finger motif, followed by a RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The RING fingers may interact with a subset of ubiquitin-conjugating enzymes (E2s), including UbcH5B, and mediate protein-protein interactions. T

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 104 RVVQKNLVFVVGLSQRLADPEVLKRPEYFGKFGKIHKVVINNSTSYAGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDG 183
Cdd:cd12438    1 RVVQKNLVYVVGLPPRLADEEVLKRPEYFGQYGKIKKIVINRSTSYAGSQGPSASAYVTYSRKEDALRAIQAVDGFVLDG 80

                         90
                 ....*....|....*...
gi 300069017 184 RTLKASLGTTKYCSYFLK 201
Cdd:cd12438   81 RTLKASFGTTKYCSSFLR 98

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 300069017   122 DPEVLKR-----PEYFGKFGKIHKVVINNSTSYAGSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGRTLKAS 189
Cdd:smart00361   1 KDEDFERelkeeEEYFGEVGKINKIYIDDVGYENHKRG---NVYITFERSEDAARAIVDLNGRYFDGRLVKAE 70

Atrophin-1 family; Atrophin-1 is the protein product of the dentatorubral-pallidoluysian atrophy (DRPLA) gene. DRPLA OMIM:125370 is a progressive neurodegenerative disorder. It is caused by the expansion of a CAG repeat in the DRPLA gene on chromosome 12p. This results in an extended polyglutamine region in atrophin-1, that is thought to confer toxicity to the protein, possibly through altering its interactions with other proteins. The expansion of a CAG repeat is also the underlying defect in six other neurodegenerative disorders, including Huntington's disease. One interaction of expanded polyglutamine repeats that is thought to be pathogenic is that with the short glutamine repeat in the transcriptional coactivator CREB binding protein, CBP. This interaction draws CBP away from its usual nuclear location to the expanded polyglutamine repeat protein aggregates that are characteriztic of the polyglutamine neurodegenerative disorders. This interferes with CBP-mediated transcription and causes cytotoxicity.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017  291 SQQISNSdtPSPPPGLSKSnPVIPISSSNHSARSPFEGAvtESQSLFSDNFRHPNPIPSGLPPFPSSPQTSSDWPTAPEP 370
Cdd:pfam03154 421 SQQLPPP--PAQPPVLTQS-QSLPPPAASHPPTSGLHQV--PSQSPFPQHPFVPGGPPPITPPSGPPTSTSSAMPGIQPP 495

                          90
                  ....*....|....*
gi 300069017  371 QSLFTSETIPVSSST 385
Cdd:pfam03154 496 SSASVSSSGPVPAAV 510

RNA recognition motif (RRM) found in Eukaryotic CCR4-NOT transcription complex subunit 4 (NOT4) and similar proteins; This subfamily corresponds to the RRM of NOT4, also termed CCR4-associated factor 4, or E3 ubiquitin-protein ligase CNOT4, or potential transcriptional repressor NOT4Hp, a component of the CCR4-NOT complex, a global negative regulator of RNA polymerase II transcription. NOT4 functions as an ubiquitin-protein ligase (E3). It contains an N-terminal C4C4 type RING finger motif, followed by a RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The RING fingers may interact with a subset of ubiquitin-conjugating enzymes (E2s), including UbcH5B, and mediate protein-protein interactions. T

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 104 RVVQKNLVFVVGLSQRLADPEVLKRPEYFGKFGKIHKVVINNSTSYAGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDG 183
Cdd:cd12438    1 RVVQKNLVYVVGLPPRLADEEVLKRPEYFGQYGKIKKIVINRSTSYAGSQGPSASAYVTYSRKEDALRAIQAVDGFVLDG 80

                         90
                 ....*....|....*...
gi 300069017 184 RTLKASLGTTKYCSYFLK 201
Cdd:cd12438   81 RTLKASFGTTKYCSSFLR 98

RING/Ubox like zinc-binding domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 300069017   14 CPLCMEPLEIDDINFFPCTCGYQICRFCWHRIRTDENGLCPACRKPY 60
Cdd:pfam14570   1 CPLCDEKLDETDKDFYPCECGYQICRFCYHDILENEGGRCPGCREPY 47

RNA recognition motif (RRM) superfamily; RRM, also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), is a highly abundant domain in eukaryotes found in proteins involved in post-transcriptional gene expression processes including mRNA and rRNA processing, RNA export, and RNA stability. This domain is 90 amino acids in length and consists of a four-stranded beta-sheet packed against two alpha-helices. RRM usually interacts with ssRNA, but is also known to interact with ssDNA as well as proteins. RRM binds a variable number of nucleotides, ranging from two to eight. The active site includes three aromatic side-chains located within the conserved RNP1 and RNP2 motifs of the domain. The RRM domain is found in a variety heterogeneous nuclear ribonucleoproteins (hnRNPs), proteins implicated in regulation of alternative splicing, and protein components of small nuclear ribonucleoproteins (snRNPs).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 300069017 111 VFVVGLSQRLaDPEVLKrpEYFGKFGKIHKVVINNStsyaGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKAS 189
Cdd:cd00590    1 LFVGNLPPDT-TEEDLR--ELFSKFGEVVSVRIVRD----RDGKSKGFAFVEFESPEDAEKALEALNGTELGGRPLKVS 72

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 300069017  13 ECPLCMEPLeiddINFFPCTCGYQICRFCWHRIRTDENGLCPAC 56
Cdd:cd16449    2 ECPICLERL----KDPVLLPCGHVFCRECIRRLLESGSIKCPIC 41

RNA recognition motif (RRM) found in Zinc finger CCHC-type and RNA-binding motif-containing protein 1 (ZCRB1) and similar proteins; This subfamily corresponds to the RRM of ZCRB1, also termed MADP-1, or U11/U12 small nuclear ribonucleoprotein 31 kDa protein (U11/U12 snRNP 31 or U11/U12-31K), a novel multi-functional nuclear factor, which may be involved in morphine dependence, cold/heat stress, and hepatocarcinoma. It is located in the nucleoplasm, but outside the nucleolus. ZCRB1 is one of the components of U11/U12 snRNPs that bind to U12-type pre-mRNAs and form a di-snRNP complex, simultaneously recognizing the 5' splice site and branchpoint sequence. ZCRB1 is characterized by an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a CCHC-type Zinc finger motif. In addition, it contains core nucleocapsid motifs, and Lys- and Glu-rich domains.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 300069017 132 FGKFGKIHKVVINNSTSYAGSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGRTLKAS 189
Cdd:cd12393   22 FSKYGKVVKVTILKDKETRKSKG---VAFVLFLDRESAHNAVRAMNNKELFGRTLKCS 76

RNA recognition motif (RRM) found in THO complex subunit 4 (THOC4) and similar proteins; This subgroup corresponds to the RRM of THOC4, also termed transcriptional coactivator Aly/REF, or ally of AML-1 and LEF-1, or bZIP-enhancing factor BEF, an mRNA transporter protein with a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It is involved in RNA transportation from the nucleus. THOC4 was initially identified as a transcription coactivator of LEF-1 and AML-1 for the TCRalpha enhancer function. In addition, THOC4 specifically binds to rhesus (RH) promoter in erythroid. It might be a novel transcription cofactor for erythroid-specific genes.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 300069017 130 EYFGKFGKIHKVVINnstsYAGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKASL 190
Cdd:cd12680   19 ELFAEFGTLKKAAVH----YDRSGRSLGTAEVVFERRADALKAMKQYNGVPLDGRPMKIQL 75

RNA recognition motif 2 (RRM2) found in granule-associated RNA binding proteins p40-TIA-1 and TIAR; This subfamily corresponds to the RRM2 of nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR), both of which are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. TIA-1 and TIAR share high sequence similarity. They are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis. TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both, TIA-1 and TIAR, bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 300069017 111 VFVVGLSQRLaDPEVLKrpEYFGKFGKIHKVVINNSTSYAGSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGRTLK 187
Cdd:cd12353    2 IFVGDLSPEI-ETEDLK--EAFAPFGEISDARVVKDTQTGKSKG---YGFVSFVKKEDAENAIQGMNGQWLGGRNIR 72

RNA recognition motif (RRM) found in vertebrate RNA binding protein fox-1 homologs and similar proteins; This subfamily corresponds to the RRM of several tissue-specific alternative splicing isoforms of vertebrate RNA binding protein Fox-1 homologs, which show high sequence similarity to the Caenorhabditis elegans feminizing locus on X (Fox-1) gene encoding Fox-1 protein. RNA binding protein Fox-1 homolog 1 (RBFOX1), also termed ataxin-2-binding protein 1 (A2BP1), or Fox-1 homolog A, or hexaribonucleotide-binding protein 1 (HRNBP1), is predominantly expressed in neurons, skeletal muscle and heart. It regulates alternative splicing of tissue-specific exons by binding to UGCAUG elements. Moreover, RBFOX1 binds to the C-terminus of ataxin-2 and forms an ataxin-2/A2BP1 complex involved in RNA processing. RNA binding protein fox-1 homolog 2 (RBFOX2), also termed Fox-1 homolog B, or hexaribonucleotide-binding protein 2 (HRNBP2), or RNA-binding motif protein 9 (RBM9), or repressor of tamoxifen transcriptional activity, is expressed in ovary, whole embryo, and human embryonic cell lines in addition to neurons and muscle. RBFOX2 activates splicing of neuron-specific exons through binding to downstream UGCAUG elements. RBFOX2 also functions as a repressor of tamoxifen activation of the estrogen receptor. RNA binding protein Fox-1 homolog 3 (RBFOX3 or NeuN or HRNBP3), also termed Fox-1 homolog C, is a nuclear RNA-binding protein that regulates alternative splicing of the RBFOX2 pre-mRNA, producing a message encoding a dominant negative form of the RBFOX2 protein. Its message is detected exclusively in post-mitotic regions of embryonic brain. Like RBFOX1, both RBFOX2 and RBFOX3 bind to the hexanucleotide UGCAUG elements and modulate brain and muscle-specific splicing of exon EIIIB of fibronectin, exon N1 of c-src, and calcitonin/CGRP. Members in this family also harbor one RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 300069017 119 RLADPEvLKrpEYFGKFGKIHKV-VINNSTsyaGSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGRTLKASLGT 192
Cdd:cd12407   11 RFRDPD-LR--QMFGQFGTILDVeIIFNER---GSKG---FGFVTFANSADADRAREKLNGTVVEGRKIEVNNAT 76

RNA recognition motif (RRM) found in the scaffold attachment factor (SAFB) family; This subfamily corresponds to the RRM domain of the SAFB family, including scaffold attachment factor B1 (SAFB1), scaffold attachment factor B2 (SAFB2), SAFB-like transcriptional modulator (SLTM), and similar proteins, which are ubiquitously expressed. SAFB1, SAFB2 and SLTM have been implicated in many diverse cellular processes including cell growth and transformation, stress response, and apoptosis. They share high sequence similarities and all contain a scaffold attachment factor-box (SAF-box, also known as SAP domain) DNA-binding motif, an RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a region rich in glutamine and arginine residues. SAFB1 is a nuclear protein with a distribution similar to that of SLTM, but unlike that of SAFB2, which is also found in the cytoplasm. To a large extent, SAFB1 and SLTM might share similar functions, such as the inhibition of an oestrogen reporter gene. The additional cytoplasmic localization of SAFB2 implies that it could play additional roles in the cytoplasmic compartment which are distinct from the nuclear functions shared with SAFB1 and SLTM.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 300069017 112 FVVGLSQ--RLADpevLKrpEYFGKFGKI--HKVVINNSTSYAGSQGpsasaYVTYIRSEDALRAIQCVNNVVVDGRTL 186
Cdd:cd12417    3 WISGLSDttKAAD---LK--KIFSKYGKVvsAKVVTSARTPGSRCYG-----YVTMASVEEADLCIKSLNKTELHGRVI 71

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 300069017  13 ECPLCMEPlEIDDINFfpcTCGYQ-ICRFCWHRIRTDENGLCPACRKPYPEDPAVYKP 69
Cdd:cd16786    4 ECTVCFDS-EVDTVIY---TCGHMcLCNSCGLKLKRQINACCPICRRVIKDVIKIYRP 57

RNA recognition motif (RRM) found in transformer-2 protein homolog TRA2-alpha, TRA2-beta and similar proteins; This subfamily corresponds to the RRM of two mammalian homologs of Drosophila transformer-2 (Tra2), TRA2-alpha, TRA2-beta (also termed SFRS10), and similar proteins found in eukaryotes. TRA2-alpha is a 40-kDa serine/arginine-rich (SR) protein that specifically binds to gonadotropin-releasing hormone (GnRH) exonic splicing enhancer on exon 4 (ESE4) and is necessary for enhanced GnRH pre-mRNA splicing. It strongly stimulates GnRH intron A excision in a dose-dependent manner. In addition, TRA2-alpha can interact with either 9G8 or SRp30c, which may also be crucial for ESE-dependent GnRH pre-mRNA splicing. TRA2-beta is a serine/arginine-rich (SR) protein that controls the pre-mRNA alternative splicing of the calcitonin/calcitonin gene-related peptide (CGRP), the survival motor neuron 1 (SMN1) protein and the tau protein. Both, TRA2-alpha and TRA2-beta, contains a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), flanked by the N- and C-terminal arginine/serine (RS)-rich regions.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 300069017 113 VVGLSQRLADPEVlkrPEYFGKFGKIHKV--VINNSTSYagSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGR 184
Cdd:cd12363    6 VFGLSLYTTERDL---REVFSRYGPIEKVqvVYDQQTGR--SRG---FGFVYFESVEDAKEAKERLNGQEIDGR 71

RING finger, HC subclass, found in tripartite motif-containing protein 26 (TRIM26) and similar proteins; TRIM26, also known as acid finger protein (AFP), RING finger protein 95 (RNF95), or zinc finger protein 173 (ZNF173), is an E3 ubiquitin-protein ligase that negatively regulates interferon-beta production and antiviral response through polyubiquitination and degradation of nuclear transcription factor IRF3. It functions as an important regulator for RNA virus-triggered innate immune response by bridging TBK1 to NEMO (NF-kappaB essential modulator, also known as IKKgamma) and mediating TBK1 activation. It also acts as a novel tumor suppressor of hepatocellular carcinoma by regulating cancer cell proliferation, colony forming ability, migration, and invasion. TRIM26 belongs 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, a B-box, and two coiled coil domains, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017   9 EDPVECPLCME----PLEIDdinffpctCGYQICRFCW--HRIRTDENG--LCPACRKPY 60
Cdd:cd16598    2 EEEVTCSICLDylrdPVTID--------CGHNFCRSCItdYCPISGGHErpVCPLCRKPF 53

RING finger, HC subclass, found in Drosophila melanogaster protein Seven-in-Absentia (sina) and its homologs; This subfamily includes the Drosophila melanogaster protein Seven-in-Absentia (sina), its mammalian orthologs, SIAH1 and SIAH2, plant SINA-related proteins, and similar proteins. Sina plays an important role in the phyllopod-dependent degradation of the transcriptional repressor tramtrack to allow the formation of the R7 photoreceptor in the developing eye of Drosophila melanogaster. Both SIAH1 and SIAH2 are E3 ubiquitin-protein ligases, mediating the ubiquitinylation and subsequent proteasomal degradation of biologically important target proteins that regulate general functions, such as cell cycle control, apoptosis, and DNA repair. They are inducible by the tumor suppressor and transcription factor p53. SIAH2 can also be regulated by sex hormones and cytokine signaling. Moreover, they share high sequence similarity, but possess contrary roles in cancer, with SIAH1 more often acting as a tumor suppressor while SIAH2 functions as a proto-oncogene. Plant SINAT1-5 are putative E3 ubiquitin ligases involved in the regulation of stress responses. All subfamily members possess two characteristic domains, an N-terminal C3HC4-type RING-HC finger and a C-terminal tumor necrosis factor (TNF) receptor associated factor (TRAF)-like substrate-binding domain (SBD).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 300069017  13 ECPLCMEPLEIDdinFFPCTCGYQICRFCWHRIrtdeNGLCPACR 57
Cdd:cd16571    2 ECPVCFEPLLPP---IYQCSNGHLLCSSCRSKL----TNKCPTCR 39

RING finger, HC subclass, found in tripartite motif-containing proteins, TRIM7, TRIM11 and TRIM27, and similar proteins; TRIM7, TRIM11 and TRIM27, closely related tripartite motif-containing proteins, belong to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM7, also known as glycogenin-interacting protein (GNIP) or RING finger protein 90 (RNF90), is an E3 ubiquitin-protein ligase that mediates c-Jun/AP-1 activation by Ras signalling. Its phosphorylation and activation by MSK1 in response to direct activation by the Ras-Raf-MEK-ERK pathway can stimulate TRIM7 E3 ubiquitin ligase activity in mediating Lys63-linked ubiquitination of the AP-1 coactivator RACO-1, leading to RACO-1 protein stabilization. Moreover, TRIM7 binds and activates glycogenin, the self-glucosylating initiator of glycogen biosynthesis. TRIM11, also known as protein BIA1, or RING finger protein 92 (RNF92), is an E3 ubiquitin-protein ligase involved in the development of the central nervous system. It is overexpressed in high-grade gliomas and promotes proliferation, invasion, migration and glial tumor growth. TRIM11 acts as a potential therapeutic target for congenital central hypoventilation syndrome (CCHS) by mediating the degradation of CCHS-associated polyalanine-expanded Phox2b. TRIM11 modulates the function of neurogenic transcription factor Pax6 through the ubiquitin-proteosome system, and thus plays an essential role for Pax6-dependent neurogenesis. It also binds to and destabilizes a key component of the activator-mediated cofactor complex (ARC105), humanin, a neuroprotective peptide against Alzheimer's disease-relevant insults, and further regulates ARC105 function in transforming growth factor beta (TGFbeta) signaling. Moreover, TRIM11 negatively regulates retinoic acid-inducible gene-I (RIG-I)-mediated interferon-beta (IFNbeta) production and antiviral activity by targeting TANK-binding kinase-1 (TBK1). It may contribute to the endogenous restriction of retroviruses in cells. It enhances N-tropic murine leukemia virus (N-MLV) entry by interfering with Ref1 restriction. It also suppresses the early steps of human immunodeficiency virus HIV-1 transduction, resulting in decreased reverse transcripts. TRIM27, also known as RING finger protein 76 (RNF76), RET finger protein (RFP), or zinc finger protein RFP, is a nuclear E3 ubiquitin-protein ligase that is highly expressed in testis and in various tumor cell lines. Expression of TRIM27 is associated with prognosis of colon and endometrial cancers. TRIM27 was first identified as a fusion partner of the RET receptor tyrosine kinase. It functions as a transcriptional repressor and associates with several proteins involved in transcriptional activity, such as enhancer of polycomb 1 (Epc1), a member of the Polycomb group proteins, and Mi-2beta, a main component of the nucleosome remodeling and deacetylase (NuRD) complex, and the cell cycle regulator retinoblastoma protein (RB1). It also interacts with HDAC1, leading to downregulation of thioredoxin binding protein 2 (TBP-2), which inhibits the function of thioredoxin. Moreover, TRIM27 mediates Pax7-induced ubiquitination of MyoD in skeletal muscle atrophy. In addition, it inhibits muscle differentiation by modulating serum response factor (SRF) and Epc1. TRIM27 promotes a non-canonical polyubiquitination of PTEN, a lipid phosphatase that catalyzes PtdIns(3,4,5)P3 (PIP3) to PtdIns(4,5)P2 (PIP2). It is an IKKepsilon-interacting protein that regulates IkappaB kinase (IKK) function and negatively regulates signaling involved in the antiviral response and inflammation. TRIM27 also forms a protein complex with MBD4 or MBD2 or MBD3, and thus plays an important role in the enhancement of transcriptional repression through MBD proteins in tumorigenesis, spermatogenesis, and embryogenesis. It is a component of an estrogen receptor 1 (ESR1) regulatory complex that is involved in estrogen receptor-mediated transcription in MCF-7 cells.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 300069017  14 CPLCME----PLEIDdinffpctCGYQICRFC----WHRirTDENGLCPACRKPYPEDP 64
Cdd:cd16594    8 CPICLDyftdPVTLD--------CGHSFCRACiarcWEE--PETSASCPQCRETCPQRN 56

RNA recognition motif 3 (RRM3) found in the Hu proteins family; This subfamily corresponds to the RRM3 of the Hu proteins family which represent a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is the ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 111 VFVVGLSQRlADPEVLKRpeYFGKFGKIHKV-VINNSTSyagsQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKAS 189
Cdd:cd12377    2 IFVYNLAPD-ADESLLWQ--LFGPFGAVQNVkIIRDFTT----NKCKGYGFVTMTNYDEAAVAIASLNGYRLGGRVLQVS 74

                 .
gi 300069017 190 L 190
Cdd:cd12377   75 F 75

RNA recognition motif (RRM) found in nucleolar protein 8 (NOL8) and similar proteins; This model corresponds to the RRM of NOL8 (also termed Nop132) encoded by a novel NOL8 gene that is up-regulated in the majority of diffuse-type, but not intestinal-type, gastric cancers. Thus, NOL8 may be a good molecular target for treatment of diffuse-type gastric cancer. Also, NOL8 is a phosphorylated protein that contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), suggesting NOL8 is likely to function as a novel RNA-binding protein. It may be involved in regulation of gene expression at the post-transcriptional level or in ribosome biogenesis in cancer cells.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 111 VFVVGLSQRLADPEVLKRpeyFGKFGKIHKVVINNSTSYAgsqgPSASAYVTYIRSEDAL-RAIQCVNNVVVDGRTLKAS 189
Cdd:cd12226    2 LFVGGLSPSITEDDLERR---FSRFGTVSDVEIIRKKDAP----DRGFAYIDLRTSEAALqKCLSTLNGVKWKGSRLKIQ 74

                 ..
gi 300069017 190 LG 191
Cdd:cd12226   75 LA 76

RNA recognition motif 2 (RRM2) found in HIV Tat-specific factor 1 (Tat-SF1) and similar proteins; This subfamily corresponds to the RRM2 of Tat-SF1 and CUS2. Tat-SF1 is the cofactor for stimulation of transcriptional elongation by human immunodeficiency virus-type 1 (HIV-1) Tat. It is a substrate of an associated cellular kinase. Tat-SF1 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a highly acidic carboxyl-terminal half. The family also includes CUS2, a yeast homolog of human Tat-SF1. CUS2 interacts with U2 RNA in splicing extracts and functions as a splicing factor that aids assembly of the splicing-competent U2 snRNP in vivo. CUS2 also associates with PRP11 that is a subunit of the conserved splicing factor SF3a. Like Tat-SF1, CUS2 contains two RRMs as well.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 300069017 134 KFGKIHKVVINnstsyagSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKASL--GTTKY 195
Cdd:cd12282   35 KFGQVKKVVVF-------DRHPDGVASVKFKEPEEADKCIQALNGRWFAGRKLEAETwdGKTDY 91

RNA recognition motif 1 (RRM1) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM1 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 111 VFVVGLSQRLADPEVLkrpEYFGKFGKIHK--VVINNstsyaGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKA 188
Cdd:cd12413    2 LFVRNLPYDTTDEQLE---ELFSDVGPVKRcfVVKDK-----GKDKCRGFGYVTFALAEDAQRALEEVKGKKFGGRKIKV 73

                 ..
gi 300069017 189 SL 190
Cdd:cd12413   74 EL 75

RNA recognition motif 3 (RRM3) found in RNA-binding protein 19 (RBM19) and RNA recognition motif 2 found in multiple RNA-binding domain-containing protein 1 (MRD1); This subfamily corresponds to the RRM3 of RBM19 and RRM2 of MRD1. RBM19, also termed RNA-binding domain-1 (RBD-1), is a nucleolar protein conserved in eukaryotes involved in ribosome biogenesis by processing rRNA and is essential for preimplantation development. It has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). MRD1 is encoded by a novel yeast gene MRD1 (multiple RNA-binding domain). It is well conserved in yeast and its homologs exist in all eukaryotes. MRD1 is present in the nucleolus and the nucleoplasm. It interacts with the 35 S precursor rRNA (pre-rRNA) and U3 small nucleolar RNAs (snoRNAs). It is essential for the initial processing at the A0-A2 cleavage sites in the 35 S pre-rRNA. MRD1 contains 5 conserved RRMs, which may play an important structural role in organizing specific rRNA processing events.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 300069017 111 VFVVGLSQRLADPEVLKRPEYFGKFGKIHkVVINNSTSYagSQGpsaSAYVTYIRSEDALRAIQCVNNVVVDGRTL 186
Cdd:cd12316    2 LFVRNLPFTATEDELRELFEAFGKISEVH-IPLDKQTKR--SKG---FAFVLFVIPEDAVKAYQELDGSIFQGRLL 71

RNA recognition motif (RRM) found in the Aly/REF family; This subfamily corresponds to the RRM of Aly/REF family which includes THO complex subunit 4 (THOC4, also termed Aly/REF), S6K1 Aly/REF-like target (SKAR, also termed PDIP3 or PDIP46) and similar proteins. THOC4 is an mRNA transporter protein with a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It is involved in RNA transportation from the nucleus, and was initially identified as a transcription coactivator of LEF-1 and AML-1 for the TCRalpha enhancer function. In addition, THOC4 specifically binds to rhesus (RH) promoter in erythroid, and might be a novel transcription cofactor for erythroid-specific genes. SKAR shows high sequence homology with THOC4 and possesses one RRM as well. SKAR is widely expressed and localizes to the nucleus. It may be a critical player in the function of S6K1 in cell and organism growth control by binding the activated, hyperphosphorylated form of S6K1 but not S6K2. Furthermore, SKAR functions as a protein partner of the p50 subunit of DNA polymerase delta. In addition, SKAR may have particular importance in pancreatic beta cell size determination and insulin secretion.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 300069017 130 EYFGKFGKIHKVVINnstsYAGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLK 187
Cdd:cd12418   19 ELFGRVGPVKSVKIN----YDRSGRSTGTAYVVFERPEDAEKAIKQFDGVLLDGQPMK 72

Double zinc ribbon domain; This domain family is found in bacteria, archaea and eukaryotes, and is approximately 60 amino acids in length. The family is found in association with pfam00156. This entry corresponds to two zinc ribbon motifs. This domain is found at the N-terminus of the ComF operon protein 3.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 300069017   11 PVECPLCMEPLEiddinffpctCGYQICRFCWHRIRTDENGLCPACRKPYPEDP 64
Cdd:pfam18912   7 PPRCPLCGAIVA----------EGGGLCAACWAELPFITEPRCPRCGKPLEEGE 50

RING finger, HC subclass, found in RING finger protein 138 (RNF138) and similar proteins; RNF138, also known as Nemo-like kinase-associated RING finger protein (NARF) or NLK-associated RING finger protein, is an E3 ubiquitin-protein ligase that plays an important role in glioma cell proliferation, apoptosis, and cell cycle. It specifically cooperates with the E2 conjugating enzyme E2-25K (Hip-2/UbcH1), regulates the ubiquitylation and degradation of T cell factor/lymphoid enhancer factor (TCF/LEF), and further suppresses Wnt-beta-catenin signaling. RNF138, together with three closely related proteins: RNF114, RNF125 and RNF166, forms a novel family of ubiquitin ligases with a C3HC4-type RING-HC finger, a C2HC-, and two C2H2-type zinc fingers, as well as a ubiquitin interacting motif (UIM).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 300069017  13 ECPLCMEPLEiDDINFFPCtcGYQICRFCWHRIRTDENGLCPACRKPY 60
Cdd:cd16544    4 TCPVCQEVLK-DPVELPPC--RHIFCKACILLALRSSGARCPLCRGPV 48

RNA recognition motif (RRM) found in RNA-binding protein with serine-rich domain 1 (RNPS1) and similar proteins; This subfamily corresponds to the RRM of RNPS1 and its eukaryotic homologs. RNPS1, also termed RNA-binding protein prevalent during the S phase, or SR-related protein LDC2, was originally characterized as a general pre-mRNA splicing activator, which activates both constitutive and alternative splicing of pre-mRNA in vitro.It has been identified as a protein component of the splicing-dependent mRNP complex, or exon-exon junction complex (EJC), and is directly involved in mRNA surveillance. Furthermore, RNPS1 is a splicing regulator whose activator function is controlled in part by CK2 (casein kinase II) protein kinase phosphorylation. It can also function as a squamous-cell carcinoma antigen recognized by T cells-3 (SART3)-binding protein, and is involved in the regulation of mRNA splicing. RNPS1 contains an N-terminal serine-rich (S) domain, a central RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and the C-terminal arginine/serine/proline-rich (RS/P) domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 300069017 130 EYFGKFGKIHKV--VINNstsyaGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTLKAS 189
Cdd:cd12365   17 EIFSVYGTVKNVdlPIDR-----EPNLPRGYAYVEFESPEDAEKAIKHMDGGQIDGQEVTVE 73

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 300069017   10 DPVECPLCMEplEIDDINFFPCTCGYqICRFCWHRIRTdENGLCPACRKP 59
Cdd:pfam13920   1 EDLLCVICLD--RPRNVVLLPCGHLC-LCEECAERLLR-KKKKCPICRQP 46

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 300069017  14 CPLCMepleidDINFFP---CTCGYQICRFCWHRIRTDE--NGLCPACRKPypedpaVYKPLSQEEL 75
Cdd:cd16554    5 CPVCL------DLYYDPymcYPCGHIFCEPCLRQLAKSSpkNTPCPLCRTT------IRRVFFQEEL 59

RING finger, HC subclass, found in mind bomb MIB1, MIB2, RGLG1, RGLG2, and similar proteins; MIBs are large, multi-domain E3 ubiquitin-protein ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. They are also responsible for TBK1 K63-linked ubiquitination and activation, promoting interferon production and controlling antiviral immunity. Moreover, MIBs selectively control responses to cytosolic RNA and regulate type I interferon transcription. Both MIB1 and MIB2 have similar domain architectures, which consist of two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region, where MIB1 and MIB2 contain three and two C3HC4-type RING-HC fingers, respectively. This model corresponds to the third RING-HC finger of MIB1, as well as the second RING-HC finger of MIB2. In addition to MIB1 and MIB2, the RING-HC fingers of RING domain ligase RGLG1, RGLG2 and similar proteins from plant are also included in this model. RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. All RGLG proteins contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 300069017  12 VECPLCMEPLEidDINFfpcTCGYQICRFCWHRIRTdenglCPACRKP 59
Cdd:cd16520    1 ILCPICMERKK--NVVF---LCGHGTCQKCAEKLKK-----CPICRKP 38

RNA recognition motif 2 (RRM2) found in yeast nucleolar protein 4 (Nop4p) and similar proteins; This subgroup corresponds to the RRM2 of Nop4p (also known as Nop77p), encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 300069017 122 DPEVLKrpEYFGKFGKIHKVVINNStsyaGSQGPSASAYVTYIRSEDALRAIQCVNNVVVDGRTL 186
Cdd:cd12675   14 KPVHLK--KLFGRYGKVVEATIPRK----KGGKLSGFAFVTMKGRKNAEEALESVNGLEIDGRPV 72

RING finger, HC subclass, found in tripartite motif-containing protein TRIM21 and similar proteins; TRIM21, also known as 52 kDa Ro protein, 52 kDa ribonucleoprotein autoantigen Ro/SS-A, Ro(SS-A), RING finger protein 81 (RNF81), or Sjoegren syndrome type A antigen (SS-A), is a ubiquitously expressed E3 ubiquitin-protein ligase and a high affinity antibody receptor uniquely expressed in the cytosol of mammalian cells. As a cytosolic Fc receptor, TRIM21 binds the Fc of virus-associated antibodies and targets the complex in the cytosol for proteasomal degradation in a process known as antibody-dependent intracellular neutralization (ADIN), and provides an intracellular immune response to protect host defense against pathogen infection. It shows remarkably broad isotype specificity as it does not only bind IgG, but also IgM and IgA. Moreover, TRIM21 promotes the cytosolic DNA sensor cGAS and the cytosolic RNA sensor RIG-I sensing of viral genomes during infection by antibody-opsonized virus. It stimulates inflammatory signaling and activates innate transcription factors, such as nuclear factor-kappaB (NF-kappaB). TRIM21 also plays an essential role in p62-regulated redox homeostasis, suggesting it may be a viable target for treating pathological conditions resulting from oxidative damage. Furthermore, TRIM21 may have implications for various autoimmune diseases associated with uncontrolled antiviral signaling through the regulation of Nmi-IFI35 complex-mediated inhibition of innate antiviral response. TRIM21 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 300069017  12 VECPLCMEPLeiddINFFPCTCGYQICRFCWHRIRTDENGLCPACRKPY 60
Cdd:cd16596   10 VTCPICLDPF----VEPVSIECGHSFCQECISQVGKGGGSVCPVCRQRF 54

RNA recognition motif 3 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM3 of Prp24, also termed U4/U6 snRNA-associated-splicing factor PRP24 (U4/U6 snRNP), an RNA-binding protein with four well conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It facilitates U6 RNA base-pairing with U4 RNA during spliceosome assembly. Prp24 specifically binds free U6 RNA primarily with RRMs 1 and 2 and facilitates pairing of U6 RNA bases with U4 RNA bases. Additionally, it may also be involved in dissociation of the U4/U6 complex during spliceosome activation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 300069017 111 VFVVGLSQRLaDPEVLKrpEYFGKFGKIHKVVINNSTSYAGSQGPSASAYVTYIRSEDALRAIQcVNNVVVDGRTLKASL 190
Cdd:cd12298    3 IRVRNLDFEL-DEEALR--GIFEKFGEIESINIPKKQKNRKGRHNNGFAFVTFEDADSAESALQ-LNGTLLDNRKISVSL 78

RING finger, HC subclass, found in tripartite motif-containing protein TRIM4 and similar proteins; TRIM4 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox2, and a coiled coil region, as well as a SPRY/B30.2 domain positioned C-terminal to the RBCC domain. TRIM4, also known as RING finger protein 87 (RNF87), is a cytoplasmic E3 ubiquitin-protein ligase that has recently evolved and is present only in higher mammals. It transiently interacts with mitochondria, induces mitochondrial aggregation and sensitizes the cells to hydrogen peroxide (H2O2) induced death. Its interaction with peroxiredoxin 1 (PRX1) is critical for the regulation of H2O2 induced cell death. Moreover, TRIM4 functions as a positive regulator of RIG-I-mediated type I interferon induction. It regulates the K63-linked ubiquitination of RIG-1 and assembly of antiviral signaling complex at the mitochondria.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 300069017   9 EDPVECPLCMEPLEiDDINFfpcTCGYQICRFCWHRIRTDENG--LCPACRkpYPEDPAVYKP 69
Cdd:cd16590    4 QEELTCPICLDYFQ-DPVSI---ECGHNFCRGCLHRNWAPGGGpfPCPECR--HPSAPAALRP 60