RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor SRSF1, SRSF4 and similar proteins; This subfamily corresponds to the RRM2 of several serine/arginine (SR) proteins that have been classified into two subgroups. The first subgroup consists of serine/arginine-rich splicing factor 4 (SRSF4 or SRp75 or SFRS4), serine/arginine-rich splicing factor 5 (SRSF5 or SRp40 or SFRS5 or HRS) and serine/arginine-rich splicing factor 6 (SRSF6 or SRp55). The second subgroup is composed of serine/arginine-rich splicing factor 1 (SRSF1 or ASF-1), serine/arginine-rich splicing factor 9 (SRSF9 or SRp30C) and plant pre-mRNA-splicing factor SF2 (SR1). These SR proteins are mainly involved in regulating constitutive and alternative pre-mRNA splicing. They also have been implicated in transcription, genomic stability, mRNA export and translation. All SR proteins in this family, except SRSF5, undergo nucleocytoplasmic shuttling, suggesting their widespread roles in gene expression. These SR proteins share a common domain architecture comprising two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides. Both domains can directly contact with RNA. The RRMs appear to determine the binding specificity and the SR domain also mediates protein-protein interactions. In addition, this subfamily includes the yeast nucleolar protein 3 (Npl3p), also termed mitochondrial targeting suppressor 1 protein, or nuclear polyadenylated RNA-binding protein 1. It is a major yeast RNA-binding protein that competes with 3'-end processing factors, such as Rna15, for binding to the nascent RNA, protecting the transcript from premature termination and coordinating transcription termination and the packaging of the fully processed transcript for export. It specifically recognizes a class of G/U-rich RNAs. Npl3p is a multi-domain protein with two RRMs, separated by a short linker and a C-terminal domain rich in glycine, arginine and serine residues.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  98 FRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLR 167
Cdd:cd12339   1 FRVVVSNLPERASWQDLKDFMRKAGEVTYADVHRDREGEGVVEFTSEEDMKRAIEKLDGTEFNGRRIRVE 70

transcription termination factor Rho; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  211 RPGRDDERRYAPRGEYRRNNRDEYRRGGRDEYRRNSRSDyRRPHDDEYRRPRGDEYRPGRDEYRRSRDDGRPSHDDEYRR 290
Cdd:PRK12678 181 RQAEAERGERGRREERGRDGDDRDRRDRREQGDRREERG-RRDGGDRRGRRRRRDRRDARGDDNREDRGDRDGDDGEGRG 259

                         90
                 ....*....|....*..
gi 19115482  291 DAYSRSpspRRDREENR 307
Cdd:PRK12678 260 GRRGRR---FRDRDRRG 273

RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor SRSF1, SRSF4 and similar proteins; This subfamily corresponds to the RRM2 of several serine/arginine (SR) proteins that have been classified into two subgroups. The first subgroup consists of serine/arginine-rich splicing factor 4 (SRSF4 or SRp75 or SFRS4), serine/arginine-rich splicing factor 5 (SRSF5 or SRp40 or SFRS5 or HRS) and serine/arginine-rich splicing factor 6 (SRSF6 or SRp55). The second subgroup is composed of serine/arginine-rich splicing factor 1 (SRSF1 or ASF-1), serine/arginine-rich splicing factor 9 (SRSF9 or SRp30C) and plant pre-mRNA-splicing factor SF2 (SR1). These SR proteins are mainly involved in regulating constitutive and alternative pre-mRNA splicing. They also have been implicated in transcription, genomic stability, mRNA export and translation. All SR proteins in this family, except SRSF5, undergo nucleocytoplasmic shuttling, suggesting their widespread roles in gene expression. These SR proteins share a common domain architecture comprising two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides. Both domains can directly contact with RNA. The RRMs appear to determine the binding specificity and the SR domain also mediates protein-protein interactions. In addition, this subfamily includes the yeast nucleolar protein 3 (Npl3p), also termed mitochondrial targeting suppressor 1 protein, or nuclear polyadenylated RNA-binding protein 1. It is a major yeast RNA-binding protein that competes with 3'-end processing factors, such as Rna15, for binding to the nascent RNA, protecting the transcript from premature termination and coordinating transcription termination and the packaging of the fully processed transcript for export. It specifically recognizes a class of G/U-rich RNAs. Npl3p is a multi-domain protein with two RRMs, separated by a short linker and a C-terminal domain rich in glycine, arginine and serine residues.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  98 FRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLR 167
Cdd:cd12339   1 FRVVVSNLPERASWQDLKDFMRKAGEVTYADVHRDREGEGVVEFTSEEDMKRAIEKLDGTEFNGRRIRVE 70

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 19115482      5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMN--------GFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVRdketgkskGFAFVEFESEEDAEKALEALNGKELDGRPLKV 73

RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain); The RRM motif is probably diagnostic of an RNA binding protein. RRMs are found in a variety of RNA binding proteins, including various hnRNP proteins, proteins implicated in regulation of alternative splicing, and protein components of snRNPs. The motif also appears in a few single stranded DNA binding proteins. The RRM structure consists of four strands and two helices arranged in an alpha/beta sandwich, with a third helix present during RNA binding in some cases The C-terminal beta strand (4th strand) and final helix are hard to align and have been omitted in the SEED alignment The LA proteins have an N terminal rrm which is included in the seed. There is a second region towards the C terminus that has some features characteriztic of a rrm but does not appear to have the important structural core of a rrm. The LA proteins are one of the main autoantigens in Systemic lupus erythematosus (SLE), an autoimmune disease.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 19115482     6 LFVGRIPPQATREDMMDFFKGYGQILDCKLMN-------GFGFVEVEDARDARDIVNDFQGKEFMGSRI 67
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRLVRdetgrskGFAFVEFEDEEDAEKAIEALNGKELGGREL 69

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 19115482     99 RLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENP-----GAGVVEFSTEEDMRNALTSLNGEVIKGQAVTL 166
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVRDKEtgkskGFAFVEFESEEDAEKALEALNGKELDGRPLKV 73

transcription termination factor Rho; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  211 RPGRDDERRYAPRGEYRRNNRDEYRRGGRDEYRRNSRSDyRRPHDDEYRRPRGDEYRPGRDEYRRSRDDGRPSHDDEYRR 290
Cdd:PRK12678 181 RQAEAERGERGRREERGRDGDDRDRRDRREQGDRREERG-RRDGGDRRGRRRRRDRRDARGDDNREDRGDRDGDDGEGRG 259

                         90
                 ....*....|....*..
gi 19115482  291 DAYSRSpspRRDREENR 307
Cdd:PRK12678 260 GRRGRR---FRDRDRRG 273

RNA recognition motif (RRM) domain [Translation, ribosomal structure and biogenesis];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 19115482  99 RLIVENLSEDVSWQDLKDVMRKAGEPT--------FTDAHRenpGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRE 168
Cdd:COG0724   3 KIYVGNLPYSVTEEDLRELFSEYGEVTsvklitdrETGRSR---GFGFVEMPDDEEAQAAIEALNGAELMGRTLKVNE 77

RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor SRSF1, SRSF4 and similar proteins; This subfamily corresponds to the RRM2 of several serine/arginine (SR) proteins that have been classified into two subgroups. The first subgroup consists of serine/arginine-rich splicing factor 4 (SRSF4 or SRp75 or SFRS4), serine/arginine-rich splicing factor 5 (SRSF5 or SRp40 or SFRS5 or HRS) and serine/arginine-rich splicing factor 6 (SRSF6 or SRp55). The second subgroup is composed of serine/arginine-rich splicing factor 1 (SRSF1 or ASF-1), serine/arginine-rich splicing factor 9 (SRSF9 or SRp30C) and plant pre-mRNA-splicing factor SF2 (SR1). These SR proteins are mainly involved in regulating constitutive and alternative pre-mRNA splicing. They also have been implicated in transcription, genomic stability, mRNA export and translation. All SR proteins in this family, except SRSF5, undergo nucleocytoplasmic shuttling, suggesting their widespread roles in gene expression. These SR proteins share a common domain architecture comprising two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides. Both domains can directly contact with RNA. The RRMs appear to determine the binding specificity and the SR domain also mediates protein-protein interactions. In addition, this subfamily includes the yeast nucleolar protein 3 (Npl3p), also termed mitochondrial targeting suppressor 1 protein, or nuclear polyadenylated RNA-binding protein 1. It is a major yeast RNA-binding protein that competes with 3'-end processing factors, such as Rna15, for binding to the nascent RNA, protecting the transcript from premature termination and coordinating transcription termination and the packaging of the fully processed transcript for export. It specifically recognizes a class of G/U-rich RNAs. Npl3p is a multi-domain protein with two RRMs, separated by a short linker and a C-terminal domain rich in glycine, arginine and serine residues.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  98 FRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLR 167
Cdd:cd12339   1 FRVVVSNLPERASWQDLKDFMRKAGEVTYADVHRDREGEGVVEFTSEEDMKRAIEKLDGTEFNGRRIRVE 70

RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor 4 (SRSF4) and similar proteins; This subfamily corresponds to the RRM2 of three serine/arginine (SR) proteins: serine/arginine-rich splicing factor 4 (SRSF4 or SRp75 or SFRS4), serine/arginine-rich splicing factor 5 (SRSF5 or SRp40 or SFRS5 or HRS), serine/arginine-rich splicing factor 6 (SRSF6 or SRp55). SRSF4 plays an important role in both, constitutive and alternative, splicing of many pre-mRNAs. It can shuttle between the nucleus and cytoplasm. SRSF5 regulates both alternative splicing and basal splicing. It is the only SR protein efficiently selected from nuclear extracts (NE) by the splicing enhancer (ESE) and is essential for enhancer activation. SRSF6 preferentially interacts with a number of purine-rich splicing enhancers (ESEs) to activate splicing of the ESE-containing exon. It is the only protein from HeLa nuclear extract or purified SR proteins that specifically binds B element RNA after UV irradiation. SRSF6 may also recognize different types of RNA sites. Members in this family contain two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 19115482  98 FRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRED 169
Cdd:cd12600   1 YRLIVENLSSRVSWQDLKDYMRQAGEVTYADAHKQRKNEGVVEFASYSDMKNAIEKLDGTELNGRKIRLVED 72

RNA recognition motif 2 (RRM2) found in vertebrate serine/arginine-rich splicing factor 5 (SRSF5); This subgroup corresponds to the RRM2 of SRSF5, also termed delayed-early protein HRS, or pre-mRNA-splicing factor SRp40, or splicing factor, arginine/serine-rich 5 (SFRS5), is an essential splicing regulatory serine/arginine (SR) protein that regulates both alternative splicing and basal splicing. It is the only SR protein efficiently selected from nuclear extracts (NE) by the splicing enhancer (ESE) and it is necessary for enhancer activation. SRSF5 also functions as a factor required for insulin-regulated splice site selection for protein kinase C (PKC) betaII mRNA. It is involved in the regulation of PKCbetaII exon inclusion by insulin via its increased phosphorylation by a phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway. Moreover, SRSF5 can regulate alternative splicing in exon 9 of glucocorticoid receptor pre-mRNA in a dose-dependent manner. SRSF5 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides. The specific RNA binding by SRSF5 requires the phosphorylation of its SR domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 19115482  91 PRPRRTGFRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRE 168
Cdd:cd12765   3 APPMRTENRLIVENLSSRVSWQDLKDFMRQAGEVTFADAHRPKLNEGVVEFASYSDLKNAIEKLSGKEINGRKIKLIE 80

RNA recognition motif 2 (RRM2) found in vertebrate serine/arginine-rich splicing factor 4 (SRSF4); This subgroup corresponds to the RRM2 of SRSF4, also termed pre-mRNA-splicing factor SRp75, or SRP001LB, or splicing factor, arginine/serine-rich 4 (SFRS4), a splicing regulatory serine/arginine (SR) protein that plays an important role in both constitutive splicing and alternative splicing of many pre-mRNAs. For instance, it interacts with heterogeneous nuclear ribonucleoproteins, hnRNP G and hnRNP E2, and further regulates the 5' splice site of tau exon 10, whose misregulation causes frontotemporal dementia. SFRS4 also induces production of HIV-1 vpr mRNA through the inhibition of the 5'-splice site of exon 3. In addition, SRSF4 activates splicing of the cardiac troponin T (cTNT) alternative exon by direct interactions with the cTNT exon 5 enhancer RNA. SRSF4 can shuttle between the nucleus and cytoplasm. It contains an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a glycine-rich region, an internal region homologous to the RRM, and a very long, highly phosphorylated C-terminal RS domains rich in serine-arginine dipeptides.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  89 KYPRPRRTGFRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRE 168
Cdd:cd12764   4 KYGPPTRTEYRLIVENLSSRCSWQDLKDYMRQAGEVTYADAHKGRKNEGVIEFVSYSDMKRALEKLDGTEVNGRKIRLVE 83

                ....*
gi 19115482 169 DPDAA 173
Cdd:cd12764  84 DKPGS 88

RNA recognition motif 1 (RRM1) found in vertebrate serine/arginine-rich splicing factor 5 (SRSF5); This subgroup corresponds to the RRM1 of SRSF5, also termed delayed-early protein HRS, or pre-mRNA-splicing factor SRp40, or splicing factor, arginine/serine-rich 5 (SFRS5). SFSF5 is an essential splicing regulatory serine/arginine (SR) protein that regulates both alternative splicing and basal splicing. It is the only SR protein efficiently selected from nuclear extracts (NE) by the splicing enhancer (ESE) and it is necessary for enhancer activation. SRSF5 also functions as a factor required for insulin-regulated splice site selection for protein kinase C (PKC) betaII mRNA. It is involved in the regulation of PKCbetaII exon inclusion by insulin via its increased phosphorylation by a phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway. Moreover, SRSF5 can regulate alternative splicing in exon 9 of glucocorticoid receptor pre-mRNA in a dose-dependent manner. SRSF5 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides. The specific RNA binding by SRSF5 requires the phosphorylation of its SR domain.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12595   1 RVFIGRLNPAAREKDVERFFKGYGRIRDIDLKRGFGFVEFEDPRDADDAVYELDGKELCNERVTI 65

RNA recognition motif 1 (RRM1) found in vertebrate serine/arginine-rich splicing factor 6 (SRSF6); This subfamily corresponds to the RRM1 of SRSF6, also termed pre-mRNA-splicing factor SRp55, which is an essential splicing regulatory serine/arginine (SR) protein that preferentially interacts with a number of purine-rich splicing enhancers (ESEs) to activate splicing of the ESE-containing exon. It is the only protein from HeLa nuclear extract or purified SR proteins that specifically binds B element RNA after UV irradiation. SRSF6 may also recognize different types of RNA sites. For instance, it does not bind to the purine-rich sequence in the calcitonin-specific ESE, but binds to a region adjacent to the purine tract. Moreover, cellular levels of SRSF6 may control tissue-specific alternative splicing of the calcitonin/ calcitonin gene-related peptide (CGRP) pre-mRNA. SRSF6 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal SR domains rich in serine-arginine dipeptides.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12596   3 RVYIGRLSYHVREKDIQRFFSGYGKLLEVDLKNGYGFVEFEDSRDADDAVYELNGKELCGERVIV 67

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 19115482   6 LFVGRIPPQATREDMMDFFKGYGQILDCKLMN-------GFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd00590   1 LFVGNLPPDTTEEDLRELFSKFGEVVSVRIVRdrdgkskGFAFVEFESPEDAEKALEALNGTELGGRPLKV 71

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 19115482 100 LIVENLSEDVSWQDLKDVMRKAGEPT----FTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLR 167
Cdd:cd00590   1 LFVGNLPPDTTEEDLRELFSKFGEVVsvriVRDRDGKSKGFAFVEFESPEDAEKALEALNGTELGGRPLKVS 72

RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain); The RRM motif is probably diagnostic of an RNA binding protein. RRMs are found in a variety of RNA binding proteins, including various hnRNP proteins, proteins implicated in regulation of alternative splicing, and protein components of snRNPs. The motif also appears in a few single stranded DNA binding proteins. The RRM structure consists of four strands and two helices arranged in an alpha/beta sandwich, with a third helix present during RNA binding in some cases The C-terminal beta strand (4th strand) and final helix are hard to align and have been omitted in the SEED alignment The LA proteins have an N terminal rrm which is included in the seed. There is a second region towards the C terminus that has some features characteriztic of a rrm but does not appear to have the important structural core of a rrm. The LA proteins are one of the main autoantigens in Systemic lupus erythematosus (SLE), an autoimmune disease.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482   100 LIVENLSEDVSWQDLKDVMRKAGEPT----FTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVT 165
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKsirlVRDETGRSKGFAFVEFEDEEDAEKAIEALNGKELGGRELK 70

RNA recognition motif (RRM) found in heterogeneous nuclear ribonucleoprotein C (hnRNP C)-related proteins; This subfamily corresponds to the RRM in the hnRNP C-related protein family, including hnRNP C proteins, Raly, and Raly-like protein (RALYL). hnRNP C proteins, C1 and C2, are produced by a single coding sequence. They are the major constituents of the heterogeneous nuclear RNA (hnRNA) ribonucleoprotein (hnRNP) complex in vertebrates. They bind hnRNA tightly, suggesting a central role in the formation of the ubiquitous hnRNP complex; they are involved in the packaging of the hnRNA in the nucleus and in processing of pre-mRNA such as splicing and 3'-end formation. Raly, also termed autoantigen p542, is an RNA-binding protein that may play a critical role in embryonic development. The biological role of RALYL remains unclear. It shows high sequence homology with hnRNP C proteins and Raly. Members of this family are characterized by an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal auxiliary domain. The Raly proteins contain a glycine/serine-rich stretch within the C-terminal regions, which is absent in the hnRNP C proteins. Thus, the Raly proteins represent a newly identified class of evolutionarily conserved autoepitopes.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 19115482   5 RLFVGRIPP-QATREDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRI 67
Cdd:cd12341   2 RIFVGNLPTdQMTKEDLEEIFSKYGKILGISLHKGYGFVQFDNEEDARAAVAGENGRTIKGQRL 65

RNA recognition motif 1 (RRM1) found in vertebrate heterogeneous nuclear ribonucleoprotein M (hnRNP M); This subgroup corresponds to the RRM1 of hnRNP M, a pre-mRNA binding protein that may play an important role in the pre-mRNA processing. It also preferentially binds to poly(G) and poly(U) RNA homopolymers. Moreover, hnRNP M is able to interact with early spliceosomes, further influencing splicing patterns of specific pre-mRNAs. hnRNP M functions as the receptor of carcinoembryonic antigen (CEA) that contains the penta-peptide sequence PELPK signaling motif. In addition, hnRNP M and another splicing factor Nova-1 work together as dopamine D2 receptor (D2R) pre-mRNA-binding proteins. They regulate alternative splicing of D2R pre-mRNA in an antagonistic manner. hnRNP M contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an unusual hexapeptide-repeat region rich in methionine and arginine residues (MR repeat motif).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 19115482  99 RLIVENLSEDVSWQDLKDVMR-KAGEPT----FTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRED 169
Cdd:cd12657   1 RVFISNIPFDVKWQTLKDLVKeKVGEVTyvelLMDAEGKSRGCAVVEFKTEESMKKAVEVLNKHSFNGRPLKVKED 76

RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor SRSF1, SRSF9 and similar proteins; This subfamily corresponds to the RRM2 of serine/arginine-rich splicing factor SRSF1, SRSF9 and similar proteins. SRSF1, also termed ASF-1, is a shuttling SR protein involved in constitutive and alternative splicing, nonsense-mediated mRNA decay (NMD), mRNA export and translation. It also functions as a splicing-factor oncoprotein that regulates apoptosis and proliferation to promote mammary epithelial cell transformation. SRSF9, also termed SRp30C, has been implicated in the activity of many elements that control splice site selection, the alternative splicing of the glucocorticoid receptor beta in neutrophils and in the gonadotropin-releasing hormone pre-mRNA. SRSF9 can also interact with other proteins implicated in alternative splicing, including YB-1, rSLM-1, rSLM-2, E4-ORF4, Nop30, and p32. Both, SRSF1 and SRSF9, contain two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal RS domains rich in serine-arginine dipeptides.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 19115482  98 FRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHREnpGAGVVEFSTEEDMRNALTSLN 155
Cdd:cd12601   1 YRVIVSGLPPTGSWQDLKDHMREAGDVCYADVYRD--GTGVVEFLRYEDMKYAVRKLD 56

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein M (hnRNP M) and similar proteins; This subfamily corresponds to the RRM1 of heterogeneous nuclear ribonucleoprotein M (hnRNP M), myelin expression factor 2 (MEF-2 or MyEF-2 or MST156) and similar proteins. hnRNP M is pre-mRNA binding protein that may play an important role in the pre-mRNA processing. It also preferentially binds to poly(G) and poly(U) RNA homopolymers. Moreover, hnRNP M is able to interact with early spliceosomes, further influencing splicing patterns of specific pre-mRNAs. hnRNP M functions as the receptor of carcinoembryonic antigen (CEA) that contains the penta-peptide sequence PELPK signaling motif. In addition, hnRNP M and another splicing factor Nova-1 work together as dopamine D2 receptor (D2R) pre-mRNA-binding proteins. They regulate alternative splicing of D2R pre-mRNA in an antagonistic manner. hnRNP M contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an unusual hexapeptide-repeat region rich in methionine and arginine residues (MR repeat motif). MEF-2 is a sequence-specific single-stranded DNA (ssDNA) binding protein that binds specifically to ssDNA derived from the proximal (MB1) element of the myelin basic protein (MBP) promoter and represses transcription of the MBP gene. MEF-2 shows high sequence homology with hnRNP M. It also contains three RRMs, which may be responsible for its ssDNA binding activity.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 19115482  99 RLIVENLSEDVSWQDLKDVMR-KAGEPT----FTDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRED 169
Cdd:cd12385   1 RVFISNIPYDYKWQDLKDLFReKVGEVTyvelFKDENGKSRGCGIVEFKDLESVQKALETMNRYELKGRKLVVKED 76

RNA recognition motif 2 (RRM2) found in vertebrate RNA-binding protein 4 (RBM4); This subgroup corresponds to the RRM2 of RBM4, a ubiquitously expressed splicing factor that has two isoforms, RBM4A (also known as Lark homolog) and RBM4B (also known as RBM30), which are very similar in structure and sequence. RBM4 may function as a translational regulator of stress-associated mRNAs and also plays a role in micro-RNA-mediated gene regulation. RBM4 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a CCHC-type zinc finger, and three alanine-rich regions within their C-terminal regions. The C-terminal region may be crucial for nuclear localization and protein-protein interaction. The RRMs, in combination with the C-terminal region, are responsible for the splicing function of RBM4.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 19115482   4 TRLFVGRIPPQATREDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12607   1 TKLHVGNISSSCTNQELRAKFEEYGPVIECDIVKDYAFVHMERAEDAMEAIRGLDNTEFQGKRMHV 66

RNA recognition motif 2 (RRM2) found in serine/arginine-rich splicing factor 1 (SRSF1) and similar proteins; This subgroup corresponds to the RRM2 of SRSF1, also termed alternative-splicing factor 1 (ASF-1), or pre-mRNA-splicing factor SF2, P33 subunit, a splicing regulatory serine/arginine (SR) protein involved in constitutive and alternative splicing, nonsense-mediated mRNA decay (NMD), mRNA export and translation. It also functions as a splicing-factor oncoprotein that regulates apoptosis and proliferation to promote mammary epithelial cell transformation. SRSF1 is a shuttling SR protein and contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), separated by a long glycine-rich spacer, and a C-terminal SR domains rich in serine-arginine dipeptides.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482  91 PRPRRTGFRLIVENLSEDVSWQDLKDVMRKAGEPTFTDAHREnpGAGVVEFSTEEDMRNALTSLN 155
Cdd:cd12767   2 PPSRRSEYRVVVSGLPPSGSWQDLKDHMREAGDVCYADVFRD--GTGVVEFVRKEDMTYAVRKLD 64

RNA recognition motif 2 (RRM2) found in Saccharomyces cerevisiae protein HRB1, G-strand-binding protein 2 (GBP2) and similar proteins; The family includes Saccharomyces cerevisiae protein HRB1 (also called protein TOM34) and GBP2, both of which are SR-like mRNA-binding proteins which shuttle from the nucleus to the cytoplasm when bound to the mature mRNA molecules. They act as quality control factors for spliced mRNAs. GBP2, also called RAP1 localization factor 6, is a single-strand telomeric DNA-binding protein that binds single-stranded telomeric sequences of the type (TG[1-3])n in vitro. It also binds to RNA. GBP2 influences the localization of RAP1 in the nuclei and plays a role in modulating telomere length. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482  97 GFRLIVENLSEDVSWQDLKDVMRKAGEPTF----TDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLR 167
Cdd:cd21606   1 GYEVFIANLPYSINWQALKDMFKECGDVLRadveLDYNGRSRGFGTVIYATEEEMHRAIDTFNGYELEGRVLEVK 75

RNA recognition motif 3 (RRM3) found found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM3 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is an ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 19115482   4 TRLFVGRIPPQATREDMMDFFKGYGQILDCKLM-------NGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12380   2 TNVYVKNFGEDVDDDELKELFEKYGKITSAKVMkddsgksKGFGFVNFENHEAAQKAVEELNGKELNGKKLYV 74

RNA recognition motif 2 (RRM2) found in Saccharomyces cerevisiae protein PES4, protein MIP6 and similar proteins; The family includes PES4 (also called DNA polymerase epsilon suppressor 4) and MIP6 (also called MEX67-interacting protein 6), both of which are predicted RNA binding proteins that may act as regulators of late translation, protection, and mRNA localization. MIP6 acts as a novel factor for nuclear mRNA export, binds to both poly(A)+ RNA and nuclear pores. It interacts with MEX67. Members in this family contain four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 19115482  13 PQATREDMMDFFKGYGQILDCKL--MNGFGFVEVEDARDARDIVNDFQGKEFMGSRI 67
Cdd:cd21602  12 PRLTTRVFYDTFKKYGKILSCKLdrRKNIGFVYFENDKAARKVIKEYNNKEFFGNKI 68

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor 3 (SRSF3) and similar proteins; This subfamily corresponds to the RRM of two serine/arginine (SR) proteins, serine/arginine-rich splicing factor 3 (SRSF3) and serine/arginine-rich splicing factor 7 (SRSF7). SRSF3, also termed pre-mRNA-splicing factor SRp20, modulates alternative splicing by interacting with RNA cis-elements in a concentration- and cell differentiation-dependent manner. It is also involved in termination of transcription, alternative RNA polyadenylation, RNA export, and protein translation. SRSF3 is critical for cell proliferation, and tumor induction and maintenance. It can shuttle between the nucleus and cytoplasm. SRSF7, also termed splicing factor 9G8, plays a crucial role in both constitutive splicing and alternative splicing of many pre-mRNAs. Its localization and functions are tightly regulated by phosphorylation. SRSF7 is predominantly present in the nuclear and can shuttle between nucleus and cytoplasm. It cooperates with the export protein, Tap/NXF1, helps mRNA export to the cytoplasm, and enhances the expression of unspliced mRNA. Moreover, SRSF7 inhibits tau E10 inclusion through directly interacting with the proximal downstream intron of E10, a clustering region for frontotemporal dementia with Parkinsonism (FTDP) mutations. Both SRSF3 and SRSF7 contain a single N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal RS domain rich in serine-arginine dipeptides. The RRM domain is involved in RNA binding, and the RS domain has been implicated in protein shuttling and protein-protein interactions.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMN---GFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12373   1 KVYVGNLGPRVTKRELEDAFEKYGPLRNVWVARnppGFAFVEFEDPRDAEDAVRALDGRRICGSRVRV 68

RNA recognition motif 2 (RRM2) found in vertebrate RRM-containing coactivator activator/modulator (CoAA); This subgroup corresponds to the RRM2 of CoAA, also termed RNA-binding protein 14 (RBM14), or paraspeckle protein 2 (PSP2), or synaptotagmin-interacting protein (SYT-interacting protein), a heterogeneous nuclear ribonucleoprotein (hnRNP)-like protein identified as a nuclear receptor coactivator. It mediates transcriptional coactivation and RNA splicing effects in a promoter-preferential manner and is enhanced by thyroid hormone receptor-binding protein (TRBP). CoAA contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a TRBP-interacting domain. It stimulates transcription through its interactions with coactivators, such as TRBP and CREB-binding protein CBP/p300, via the TRBP-interacting domain and interaction with an RNA-containing complex, such as DNA-dependent protein kinase-poly(ADP-ribose) polymerase complexes, via the RRMs.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12609   2 KIFVGNVSATCTSDELRGLFEEFGRVVECDKVKDYAFVHMEREEEALAAIEALNGKEVKGRRINV 66

RNA recognition motif (RRM) found in RNA-binding protein RBM8A, RBM8B nd similar proteins; This subfamily corresponds to the RRM of RBM8, also termed binder of OVCA1-1 (BOV-1), or RNA-binding protein Y14, which is one of the components of the exon-exon junction complex (EJC). It has two isoforms, RBM8A and RBM8B, both of which are identical except that RBM8B is 16 amino acids shorter at its N-terminus. RBM8, together with other EJC components (such as Magoh, Aly/REF, RNPS1, Srm160, and Upf3), plays critical roles in postsplicing processing, including nuclear export and cytoplasmic localization of the mRNA, and the nonsense-mediated mRNA decay (NMD) surveillance process. RBM8 binds to mRNA 20-24 nucleotides upstream of a spliced exon-exon junction. It is also involved in spliced mRNA nuclear export, and the process of nonsense-mediated decay of mRNAs with premature stop codons. RBM8 forms a specific heterodimer complex with the EJC protein Magoh which then associates with Aly/REF, RNPS1, DEK, and SRm160 on the spliced mRNA, and inhibits ATP turnover by eIF4AIII, thereby trapping the EJC core onto RNA. RBM8 contains an N-terminal putative bipartite nuclear localization signal, one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), in the central region, and a C-terminal serine-arginine rich region (SR domain) and glycine-arginine rich region (RG domain).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 19115482   6 LFVGRIPPQATREDMMDFFKGYGQILDCKL--------MNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12324   9 IFVTGVHEEAQEEDIHDKFAEFGEIKNLHLnldrrtgfVKGYALVEYETKKEAQAAIEGLNGKELLGQTISV 80

RNA recognition motif 3 (RRM3) found in CELF/Bruno-like family of RNA binding proteins CELF1, CELF2, CELF3, CELF4, CELF5, CELF6 and similar proteins; This subgroup corresponds to the RRM3 of the CUGBP1 and ETR-3-like factors (CELF) or BRUNOL (Bruno-like) proteins, a family of structurally related RNA-binding proteins involved in the regulation of pre-mRNA splicing in the nucleus and in the control of mRNA translation and deadenylation in the cytoplasm. The family contains six members: CELF-1 (also termed BRUNOL-2, or CUG-BP1, or NAPOR, or EDEN-BP), CELF-2 (also termed BRUNOL-3, or ETR-3, or CUG-BP2, or NAPOR-2), CELF-3 (also termed BRUNOL-1, or TNRC4, or ETR-1, or CAGH4, or ER DA4), CELF-4 (also termed BRUNOL-4), CELF-5 (also termed BRUNOL-5), CELF-6 (also termed BRUNOL-6). They all contain three highly conserved RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains): two consecutive RRMs (RRM1 and RRM2) situated in the N-terminal region followed by a linker region and the third RRM (RRM3) close to the C-terminus of the protein. The low sequence conservation of the linker region is highly suggestive of a large variety in the co-factors that associate with the various CELF family members. Based on both sequence similarity and function, the CELF family can be divided into two subfamilies, the first containing CELFs 1 and 2, and the second containing CELFs 3, 4, 5, and 6. The different CELF proteins may act through different sites on at least some substrates. Furthermore, CELF proteins may interact with each other in varying combinations to influence alternative splicing in different contexts.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 19115482   6 LFVGRIPPQATREDMMDFFKGYGQILDCKLM--------NGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12362   1 LFVYHLPNEFTDQDLYQLFAPFGNVVSAKVFvdkntgrsKGFGFVSYDNPLSAQAAIKAMNGFQVGGKRLKV 72

RNA recognition motif (RRM) found in heterogeneous nuclear ribonucleoprotein G (hnRNP G), Y chromosome RNA recognition motif 1 (hRBMY), testis-specific heterogeneous nuclear ribonucleoprotein G-T (hnRNP G-T) and similar proteins; This subfamily corresponds to the RRM domain of hnRNP G, also termed glycoprotein p43 or RBMX, an RNA-binding motif protein located on the X chromosome. It is expressed ubiquitously and has been implicated in the splicing control of several pre-mRNAs. Moreover, hnRNP G may function as a regulator of transcription for SREBP-1c and GnRH1. Research has shown that hnRNP G may also act as a tumor-suppressor since it upregulates the Txnip gene and promotes the fidelity of DNA end-joining activity. In addition, hnRNP G appears to play a critical role in proper neural development of zebrafish and frog embryos. The family also includes several paralogs of hnRNP G, such as hRBMY and hnRNP G-T (also termed RNA-binding motif protein, X-linked-like-2). Both, hRBMY and hnRNP G-T, are exclusively expressed in testis and critical for male fertility. Like hnRNP G, hRBMY and hnRNP G-T interact with factors implicated in the regulation of pre-mRNA splicing, such as hTra2-beta1 and T-STAR. Although members in this family share a high conserved N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), they appear to recognize different RNA targets. For instance, hRBMY interacts specifically with a stem-loop structure in which the loop is formed by the sequence CA/UCAA. In contrast, hnRNP G associates with single stranded RNA sequences containing a CCA/C motif. In addition to the RRM, hnRNP G contains a nascent transcripts targeting domain (NTD) in the middle region and a novel auxiliary RNA-binding domain (RBD) in its C-terminal region. The C-terminal RBD exhibits distinct RNA binding specificity, and would play a critical role in the regulation of alternative splicing by hnRNP G.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 19115482   4 TRLFVGRIPPQATREDMMDFFKGYGQILDCKLMN--------GFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12382   2 GKLFIGGLNTETNEKALEAVFGKYGRIVEVLLMKdretnksrGFAFVTFESPADAKDAARDMNGKELDGKAIKV 75

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482     4 TRLFVGRIPPQATREDMMDFFKGYGQILDCKLM-------NGFGFVEVEDARDARDIVNDFQGKEFMGSRIVVEPARGER 76
Cdd:TIGR01628  89 GNIFVKNLDKSVDNKALFDTFSKFGNILSCKVAtdengksRGYGFVHFEKEESAKAAIQKVNGMLLNDKEVYVGRFIKKH 168

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482    77 RRRENfresaaskyPRPRRTgfRLIVENLSEDVSWQDLKDVMRKAGEPT----FTDAHRENPGAGVVEFSTEEDMRNALT 152
Cdd:TIGR01628 169 EREAA---------PLKKFT--NLYVKNLDPSVNEDKLRELFAKFGEITsaavMKDGSGRSRGFAFVNFEKHEDAAKAVE 237

                         170
                  ....*....|.
gi 19115482   153 SLNGEVIKGQA 163
Cdd:TIGR01628 238 EMNGKKIGLAK 248

RNA recognition motif 2 (RRM2) found in squamous cell carcinoma antigen recognized by T-cells 3 (SART3) and similar proteins; This subfamily corresponds to the RRM2 of SART3, also termed Tat-interacting protein of 110 kDa (Tip110), is an RNA-binding protein expressed in the nucleus of the majority of proliferating cells, including normal cells and malignant cells, but not in normal tissues except for the testes and fetal liver. It is involved in the regulation of mRNA splicing probably via its complex formation with RNA-binding protein with a serine-rich domain (RNPS1), a pre-mRNA-splicing factor. SART3 has also been identified as a nuclear Tat-interacting protein that regulates Tat transactivation activity through direct interaction and functions as an important cellular factor for HIV-1 gene expression and viral replication. In addition, SART3 is required for U6 snRNP targeting to Cajal bodies. It binds specifically and directly to the U6 snRNA, interacts transiently with the U6 and U4/U6 snRNPs, and promotes the reassembly of U4/U6 snRNPs after splicing in vitro. SART3 contains an N-terminal half-a-tetratricopeptide repeat (HAT)-rich domain, a nuclearlocalization signal (NLS) domain, and two C-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLMN-------GFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12392   4 KLFVKGLPFSCTKEELEELFKQHGTVKDVRLVTyrngkpkGLAYVEYENEADASQAVLKTDGTEIKDHTISV 75

RNA recognition motif (RRM) found in fission yeast pre-mRNA-splicing factor Srp1p, Arabidopsis thaliana arginine/serine-rich-splicing factor RSp31 and similar proteins; This subfamily corresponds to the RRM of Srp1p and RRM2 of plant SR splicing factors. Srp1p is encoded by gene srp1 from fission yeast Schizosaccharomyces pombe. It plays a role in the pre-mRNA splicing process, but is not essential for growth. Srp1p is closely related to the SR protein family found in Metazoa. It contains an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a glycine hinge and a RS domain in the middle, and a C-terminal domain. The family also includes a novel group of arginine/serine (RS) or serine/arginine (SR) splicing factors existing in plants, such as A. thaliana RSp31, RSp35, RSp41 and similar proteins. Like vertebrate RS splicing factors, these proteins function as plant splicing factors and play crucial roles in constitutive and alternative splicing in plants. They all contain two RRMs at their N-terminus and an RS domain at their C-terminus.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 19115482   6 LFVGRIPPQATR-EDMMDFFKGYGQILDCKLMNGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12233   2 LFVVGFDPGTTReEDIEKLFEPFGPLVRCDIRKTFAFVEFEDSEDATKALEALHGSRIDGSVLTV 66

RNA recognition motif 1 (RRM1) found in yeast nucleolar protein 4 (Nop4p) and similar proteins; This subgroup corresponds to the RRM1 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        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 19115482   4 TRLFVGRIPPQATREDMMDFFKGYGQILDCKLMN--------GFGFVEVEDARDARDIVNDFQGKEFMGSRI 67
Cdd:cd12674   1 TTLFVRNLPFDVTLESLTDFFSDIGPVKHAVVVTdpetkksrGYGFVSFSTHDDAEEALAKLKNRKLSGHIL 72

RNA recognition motif 2 (RRM2) found in Nicotiana sylvestris chloroplastic 33 kDa ribonucleoprotein (NsCP33) and similar proteins; The family includes NsCP33, Arabidopsis thaliana chloroplastic 31 kDa ribonucleoprotein (CP31A) and mitochondrial glycine-rich RNA-binding protein 2 (AtGR-RBP2). NsCP33 may be involved in splicing and/or processing of chloroplast RNA's. AtCP31A, also called RNA-binding protein 1/2/3 (AtRBP33), or RNA-binding protein CP31A, or RNA-binding protein RNP-T, or RNA-binding protein cp31, is required for specific RNA editing events in chloroplasts and stabilizes specific chloroplast mRNAs, as well as for normal chloroplast development under cold stress conditions by stabilizing transcripts of numerous mRNAs under these conditions. CP31A may modulate telomere replication through RNA binding domains. AtGR-RBP2, also called AtRBG2, or glycine-rich protein 2 (AtGRP2), or mitochondrial RNA-binding protein 1a (At-mRBP1a), plays a role in RNA transcription or processing during stress. It binds RNAs and DNAs sequence with a preference to single-stranded nucleic acids. AtGR-RBP2 displays strong affinity to poly(U) sequence. It exerts cold and freezing tolerance, probably by exhibiting an RNA chaperone activity during the cold and freezing adaptation process. Some members in this family contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 19115482  99 RLIVENLSEDVSWQDLKDVMRKAGEptFTDAH----RE---NPGAGVVEFSTEEDMRNALTSLNGEVIKGQAVTLRE 168
Cdd:cd21608   1 KLYVGNLSWDTTEDDLRDLFSEFGE--VESAKvitdREtgrSRGFGFVTFSTAEAAEAAIDALNGKELDGRSIVVNE 75

RNA recognition motif 2 (RRM2) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM2 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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482  99 RLIVENLSEDVSWQDLKDVMRKAG---EPTF-TDAHRENPGAGVVEFSTEEDMRNALTSLNGEVIKGQAV 164
Cdd:cd12414   1 RLIVRNLPFKCTEDDLKKLFSKFGkvlEVTIpKKPDGKLRGFAFVQFTNVADAAKAIKGMNGKKIKGRPV 70

RNA recognition motif 1 (RRM1) found in plant pre-mRNA-splicing factor SF2 and similar proteins; This subgroup corresponds to the RRM1 of SF2, also termed SR1 protein, a plant serine/arginine (SR)-rich phosphoprotein similar to the mammalian splicing factor SF2/ASF. It promotes splice site switching in mammalian nuclear extracts. SF2 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal domain rich in proline, serine and lysine residues (PSK domain), a composition reminiscent of histones. This PSK domain harbors a putative phosphorylation site for the mitotic kinase cyclin/p34cdc2.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 19115482   5 RLFVGRIPPQATREDMMDFFKGYGQILDCKLM-----NGFGFVEVEDARDARDIVNDFQGKEFMGSRIVV 69
Cdd:cd12599   1 RVYVGNLPMDIREREVEDLFSKYGPVVSIDLKipprpPAYAFVEFEDARDAEDAIRGRDGYDFDGHRLRV 70