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 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKRT 220
Cdd:cd12551   1 SVYVGNVDYGSTADELEAHFNGCGPINRVTILCDKFSGHPKGYAYIEFATRSSVQAAVALDESSFRGRVIKVLPKRT 77

RNA recognition motif in vertebrate type II embryonic polyadenylate-binding protein 2 (ePABP-2); This subgroup corresponds to the RRM of ePABP-2, also termed embryonic poly(A)-binding protein 2, or poly(A)-binding protein nuclear-like 1 (PABPN1L). ePABP-2 is a novel embryonic-specific cytoplasmic type II poly(A)-binding protein that is expressed during the early stages of vertebrate development and in adult ovarian tissue. It may play an important role in the poly(A) metabolism of stored mRNAs during early vertebrate development. ePABP-2 shows significant sequence similarity to the ubiquitously expressed nuclear polyadenylate-binding protein 2 (PABP-2 or PABPN1). Like PABP-2, ePABP-2 contains one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is responsible for the poly(A) binding. In addition, it possesses an acidic N-terminal domain predicted to form a coiled-coil and an arginine-rich C-terminal domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKRT 220
Cdd:cd12551   1 SVYVGNVDYGSTADELEAHFNGCGPINRVTILCDKFSGHPKGYAYIEFATRSSVQAAVALDESSFRGRVIKVLPKRT 77

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:COG0724   3 KIYVGNLPYSVTEEDLRELFSEYGEVTSVKLITDRETGRSRGFGFVEMPDDEEAQAAIeALNGAELMGRTLKV 75

splicing factor, CC1-like family; This model represents a subfamily of RNA splicing factors including the Pad-1 protein (N. crassa), CAPER (M. musculus) and CC1.3 (H.sapiens). These proteins are characterized by an N-terminal arginine-rich, low complexity domain followed by three (or in the case of 4 H. sapiens paralogs, two) RNA recognition domains (rrm: pfam00706). These splicing factors are closely related to the U2AF splicing factor family (TIGR01642). A homologous gene from Plasmodium falciparum was identified in the course of the analysis of that genome at TIGR and was included in the seed.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 55925591   107 RKATEEERAEVRQLLSPETVDCFFSRTSKENV---EADHRSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHP 183
Cdd:TIGR01622  76 RRRRGDSYRRRRDDRRSRREKPRARDGTPEPLtedERDRRTVFVQQLAARARERDLYEFFSKVGKVRDVQIIKDRNSRRS 155

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 55925591   184 KGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKR----------TNFPGISSTDRGGLRTHSGN 239
Cdd:TIGR01622 156 KGVGYVEFYDVDSVQAALALTGQKLLGIPVIVQLSEaeknraaraaTETSGHHPNSIPFHRLYVGN 221

RNA recognition motif in vertebrate type II embryonic polyadenylate-binding protein 2 (ePABP-2); This subgroup corresponds to the RRM of ePABP-2, also termed embryonic poly(A)-binding protein 2, or poly(A)-binding protein nuclear-like 1 (PABPN1L). ePABP-2 is a novel embryonic-specific cytoplasmic type II poly(A)-binding protein that is expressed during the early stages of vertebrate development and in adult ovarian tissue. It may play an important role in the poly(A) metabolism of stored mRNAs during early vertebrate development. ePABP-2 shows significant sequence similarity to the ubiquitously expressed nuclear polyadenylate-binding protein 2 (PABP-2 or PABPN1). Like PABP-2, ePABP-2 contains one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is responsible for the poly(A) binding. In addition, it possesses an acidic N-terminal domain predicted to form a coiled-coil and an arginine-rich C-terminal domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKRT 220
Cdd:cd12551   1 SVYVGNVDYGSTADELEAHFNGCGPINRVTILCDKFSGHPKGYAYIEFATRSSVQAAVALDESSFRGRVIKVLPKRT 77

RNA recognition motif in type II polyadenylate-binding proteins; This subfamily corresponds to the RRM of type II polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 2 (PABP-2 or PABPN1), embryonic polyadenylate-binding protein 2 (ePABP-2 or PABPN1L) and similar proteins. PABPs are 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. ePABP-2 is predominantly located in the cytoplasm and PABP-2 is located in the nucleus. In contrast to the type I PABPs containing four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), the type II PABPs contains a single highly-conserved RRM. This subfamily also includes Saccharomyces cerevisiae RBP29 (SGN1, YIR001C) gene encoding cytoplasmic mRNA-binding protein Rbp29 that binds preferentially to poly(A). Although not essential for cell viability, Rbp29 plays a role in modulating the expression of cytoplasmic mRNA. Like other type II PABPs, Rbp29 contains one RRM only.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVL 216
Cdd:cd12306   1 SIYVGNVDYGTTPEELQAHFKSCGTINRVTILCDKFTGQPKGFAYIEFVDKSSVENALLLNESEFRGRQIKVT 73

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 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKfSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd00590   1 LFVGNLPPDTTEEDLRELFSKFGEVVSVRIVRDR-DGKSKGFAFVEFESPEDAEKALeALNGTELGGRPLKV 71

RNA recognition motif 2 (RRM2) found in RNA-binding protein 34 (RBM34) and similar proteins; This subfamily corresponds to the RRM2 of RBM34, a putative RNA-binding protein containing two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). Although the function of RBM34 remains unclear currently, its RRM domains may participate in mRNA processing. RBM34 may act as an mRNA processing-related protein.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12395   1 SVFVGNLPFDIEEEELRKHFEDCGDVEAVRIVRDRETGIGKGFGYVLFKDKDSVDLALKLNGSKLRGRKLRV 72

RNA recognition motif (RRM) found in Saccharomyces cerevisiae nucleolar protein 6 (Nop6) and similar proteins; This subfamily corresponds to the RRM of Nop6, also known as Ydl213c, a component of 90S pre-ribosomal particles in yeast S. cerevisiae. It is enriched in the nucleolus and is required for 40S ribosomal subunit biogenesis. Nop6 is a non-essential putative RNA-binding protein with two N-terminal putative nuclear localisation sequences (NLS-1 and NLS-2) and an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It binds to the pre-rRNA early during transcription and plays an essential role in pre-rRNA processing.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12400   3 LFVGNLPYDTTAEDLKEHFKKAGEPPSVRLLTDKKTGKSKGCAFVEFDNQKALQKALKLHHTSLGGRKINV 73

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 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd21608   2 LYVGNLSWDTTEDDLRDLFSEFGEVESAKVITDRETGRSRGFGFVTFSTAEAAEAAIdALNGKELDGRSIVV 73

RNA recognition motif 2 (RRM2) found in Arabidopsis thaliana phragmoplastin interacting protein 1 (PHIP1) and similar proteins; The CD corresponds to the RRM2 of PHIP1. A. thaliana PHIP1 and its homologs represent a novel class of plant-specific RNA-binding proteins that may play a unique role in the polarized mRNA transport to the vicinity of the cell plate. The family members consist of multiple functional domains, including a lysine-rich domain (KRD domain) that contains three nuclear localization motifs (KKKR/NK), two RNA recognition motifs (RRMs), and three CCHC-type zinc fingers. PHIP1 is a peripheral membrane protein and is localized at the cell plate during cytokinesis in plants. In addition to phragmoplastin, PHIP1 interacts with two Arabidopsis small GTP-binding proteins, Rop1 and Ran2. However, PHIP1 interacted only with the GTP-bound form of Rop1 but not the GDP-bound form. It also binds specifically to Ran2 mRNA.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12272   1 TVYIGNLAWDIDEDDLRELFAECCEITNVRLHTDKETGEFKGYGHVEFADEESLDAALKLAGTKLCGRPIRV 72

RNA recognition motif 1 (RRM1) found in squamous cell carcinoma antigen recognized by T-cells 3 (SART3) and similar proteins; This subfamily corresponds to the RRM1 of SART3, also termed Tat-interacting protein of 110 kDa (Tip110), 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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDkFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGR 211
Cdd:cd12391   1 TVFVSNLDYSVPEDKIREIFSGCGEITDVRLVKN-YKGKSKGYCYVEFKDEESAQKALKLDRQPVEGR 67

RNA recognition motif 1 (RRM1) 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 first RRM motif.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKfsGHPKGYAYIEFASHRSVKAAVG-LDESTFRGRVIKV 215
Cdd:cd21605   3 SIFVGNLPFDCTWEDLKDHFSQVGEVIRADIVTSR--GRHRGMGTVEFTNKEDVDRAISkFDHTMFMGREIFV 73

RNA recognition motif 2 (RRM2) found in nucleolin-like proteins mainly from plants; This subfamily corresponds to the RRM2 of a group of plant nucleolin-like proteins, including nucleolin 1 (also termed protein nucleolin like 1) and nucleolin 2 (also termed protein nucleolin like 2, or protein parallel like 1). They play roles in the regulation of ribosome synthesis and in the growth and development of plants. Like yeast nucleolin, nucleolin-like proteins possess two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 55925591 144 SVFVGNVDYG----GSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12451   1 TIFVKGFDASlgedTIRDELREHFGECGEVTNVRIPTDRETGELKGFAYIEFSTKEAKEKALELNGSDIAGGNLVV 76

RNA recognition motif 1 (RRM1) found in nucleolin-like proteins mainly from plants; This subfamily corresponds to the RRM1 of a group of plant nucleolin-like proteins, including nucleolin 1 (also termed protein nucleolin like 1) and nucleolin 2 (also termed protein nucleolin like 2, or protein parallel like 1). They play roles in the regulation of ribosome synthesis and in the growth and development of plants. Like yeast nucleolin, nucleolin-like proteins possess two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12450   1 TLFVGNLSWSATQDDLENFFSDCGEVVDVRIAMDRDDGRSKGFGHVEFASAESAQKALEKSGQDLGGREIRL 72

RNA recognition motif 2 (RRM2) found in yeast nucleolar protein 12 (Nop12p) and similar proteins; This subgroup corresponds to the RRM2 of Nop12p, which is encoded by YOL041C from Saccharomyces cerevisiae. It is a novel nucleolar protein required for pre-25S rRNA processing and normal rates of cell growth at low temperatures. Nop12p shares high sequence similarity with nucleolar protein 13 (Nop13p). Both, Nop12p and Nop13p, are not essential for growth. However, unlike Nop13p that localizes primarily to the nucleolus but is also present in the nucleoplasm to a lesser extent, Nop12p is localized to the nucleolus. Nop12p contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDES-TFRGRVIKV 215
Cdd:cd12670   1 CVFVGNLAFEAEEEGLWRYFGKCGAIESVRIVRDPKTNVGKGFAYVQFKDENAVEKALLLNEKpTMKGRKLRV 73

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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILC---DKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12298   1 REIRVRNLDFELDEEALRGIFEKFGEIESINIPKkqkNRKGRHNNGFAFVTFEDADSAESALQLNGTLLDNRKISV 76

RNA recognition motif (RRM) found in U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) and similar proteins; This subfamily corresponds to the RRM of U1-70K, also termed snRNP70, a key component of the U1 snRNP complex, which is one of the key factors facilitating the splicing of pre-mRNA via interaction at the 5' splice site, and is involved in regulation of polyadenylation of some viral and cellular genes, enhancing or inhibiting efficient poly(A) site usage. U1-70K plays an essential role in targeting the U1 snRNP to the 5' splice site through protein-protein interactions with regulatory RNA-binding splicing factors, such as the RS protein ASF/SF2. Moreover, U1-70K protein can specifically bind to stem-loop I of the U1 small nuclear RNA (U1 snRNA) contained in the U1 snRNP complex. It also mediates the binding of U1C, another U1-specific protein, to the U1 snRNP complex. U1-70K contains a conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by an adjacent glycine-rich region at the N-terminal half, and two serine/arginine-rich (SR) domains at the C-terminal half. The RRM is responsible for the binding of stem-loop I of U1 snRNA molecule. Additionally, the most prominent immunodominant region that can be recognized by auto-antibodies from autoimmune patients may be located within the RRM. The SR domains are involved in protein-protein interaction with SR proteins that mediate 5' splice site recognition. For instance, the first SR domain is necessary and sufficient for ASF/SF2 Binding. The family also includes Drosophila U1-70K that is an essential splicing factor required for viability in flies, but its SR domain is dispensable. The yeast U1-70k doesn't contain easily recognizable SR domains and shows low sequence similarity in the RRM region with other U1-70k proteins and therefore not included in this family. The RRM domain is dispensable for yeast U1-70K function.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAA 200
Cdd:cd12236   2 KTLFVARLSYDTTESKLRREFEKYGPIKRVRLVRDKKTGKSRGYAFIEFEHERDMKAA 59

RNA recognition motif (RRM) found in Saccharomyces cerevisiae U1 small nuclear ribonucleoprotein SNP1 and similar proteins; SNP1, also called U1 snRNP protein SNP1, or U1 small nuclear ribonucleoprotein 70 kDa homolog, or U1 70K, or U1 snRNP 70 kDa homolog, interacts with mRNA and is involved in nuclear mRNA splicing. It is a component of the spliceosome, where it is associated with snRNP U1 by binding stem loop I of U1 snRNA. Members in this family contain an N-terminal U1snRNP70 domain and an RNA recognition motif (RRM), also called RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV------GLDES--------TF 208
Cdd:cd21615  19 KTLFVGRLDYSLTELELQKKFSKFGEIEKIRIVRDKETGKSRGYAFIVFKSESDAKNAFkegnglRGLKIndrtcivdIE 98

                        90
                ....*....|..
gi 55925591 209 RGRVIKV-LPKR 219
Cdd:cd21615  99 RGRTVKNwKPRR 110

RNA recognition motif 1 and 2 (RRM1, RRM2) found in Arabidopsis thaliana CTC-interacting domain protein CID8, CID9, CID10, CID11, CID12, CID 13 and similar proteins; This subgroup corresponds to the RRM domains found in A. thaliana CID8, CID9, CID10, CID11, CID12, CID 13 and mainly their plant homologs. These highly related RNA-binding proteins contain an N-terminal PAM2 domain (PABP-interacting motif 2), two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a basic region that resembles a bipartite nuclear localization signal. The biological role of this family remains unclear.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKfsgHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKRT 220
Cdd:cd12225   1 RTIHVGGIDGSLSEDELADYFSNCGEVTQVRLCGDR---VHTRFAWVEFATDASALSALNLDGTTLGGHPLRVSPSKT 75

RNA recognition motif (RRM) found in cleavage stimulation factor subunit 2 (CSTF2), cleavage stimulation factor subunit 2 tau variant (CSTF2T) and similar proteins; This subgroup corresponds to the RRM domain of CSTF2, its tau variant and eukaryotic homologs. CSTF2, also termed cleavage stimulation factor 64 kDa subunit (CstF64), is the vertebrate conterpart of yeast mRNA 3'-end-processing protein RNA15. It is expressed in all somatic tissues and is one of three cleavage stimulatory factor (CstF) subunits required for polyadenylation. CstF64 contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a CstF77-binding domain, a repeated MEARA helical region and a conserved C-terminal domain reported to bind the transcription factor PC-4. During polyadenylation, CstF interacts with the pre-mRNA through the RRM of CstF64 at U- or GU-rich sequences within 10 to 30 nucleotides downstream of the cleavage site. CSTF2T, also termed tauCstF64, is a paralog of the X-linked cleavage stimulation factor CstF64 protein that supports polyadenylation in most somatic cells. It is expressed during meiosis and subsequent haploid differentiation in a more limited set of tissues and cell types, largely in meiotic and postmeiotic male germ cells, and to a lesser extent in brain. The loss of CSTF2T will cause male infertility, as it is necessary for spermatogenesis and fertilization. Moreover, CSTF2T is required for expression of genes involved in morphological differentiation of spermatids, as well as for genes having products that function during interaction of motile spermatozoa with eggs. It promotes germ cell-specific patterns of polyadenylation by using its RRM to bind to different sequence elements downstream of polyadenylation sites than does CstF64.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12671   7 RSVFVGNIPYEATEEQLKDIFSEVGPVVSFRLVYDRETGKPKGYGFCEYQDQETALSAMrNLNGYELNGRALRV 80

RNA recognition motif 1 (RRM1) found in yeast protein gar2 and similar proteins; This subfamily corresponds to the RRM1 of yeast protein gar2, a novel nucleolar protein required for 18S rRNA and 40S ribosomal subunit accumulation. It shares similar domain architecture with nucleolin from vertebrates and NSR1 from Saccharomyces cerevisiae. The highly phosphorylated N-terminal domain of gar2 is made up of highly acidic regions separated from each other by basic sequences, and contains multiple phosphorylation sites. The central domain of gar2 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RGG (or GAR) domain of gar2 is rich in glycine, arginine and phenylalanine residues.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDEST-FRGRVIKV 215
Cdd:cd12447   1 TLFVGGLSWNVDDPWLKKEFEKYGGVISARVITDRGSGRSKGYGYVDFATPEAAQKALAAMSGKeIDGRQINV 73

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 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12382   4 LFIGGLNTETNEKALEAVFGKYGRIVEVLLMKDRETNKSRGFAFVTFESPADAKDAArDMNGKELDGKAIKV 75

RNA recognition motif (RRM) found in AZoospermia (DAZ) autosomal homologs, DAZL (DAZ-like) and BOULE; This subfamily corresponds to the RRM domain of two Deleted in AZoospermia (DAZ) autosomal homologs, DAZL (DAZ-like) and BOULE. BOULE is the founder member of the family and DAZL arose from BOULE in an ancestor of vertebrates. The DAZ gene subsequently originated from a duplication transposition of the DAZL gene. Invertebrates contain a single DAZ homolog, BOULE, while vertebrates, other than catarrhine primates, possess both BOULE and DAZL genes. The catarrhine primates possess BOULE, DAZL, and DAZ genes. The family members encode closely related RNA-binding proteins that are required for fertility in numerous organisms. These proteins contain an RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a varying number of copies of a DAZ motif, believed to mediate protein-protein interactions. DAZL and BOULE contain a single copy of the DAZ motif, while DAZ proteins can contain 8-24 copies of this repeat. Although their specific biochemical functions remain to be investigated, DAZL proteins may interact with poly(A)-binding proteins (PABPs), and act as translational activators of specific mRNAs during gametogenesis.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKfSGHPKGYAYIEFASHRSVKAAVGLDES-TFRGRVIKVLP 217
Cdd:cd12412   5 IFVGGIDWDTTEEELREFFSKFGKVKDVKIIKDR-AGVSKGYGFVTFETQEDAEKIQKWGANlVFKGKKLNVGP 77

RNA recognition motif (RRM) found in eukaryotic translation initiation factor 4H (eIF-4H) and similar proteins; This subfamily corresponds to the RRM of eIF-4H, also termed Williams-Beuren syndrome chromosomal region 1 protein, which, together with elf-4B/eIF-4G, serves as the accessory protein of RNA helicase eIF-4A. eIF-4H contains a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It stimulates protein synthesis by enhancing the helicase activity of eIF-4A in the initiation step of mRNA translation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCgEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12401   8 AYVGNLPFNTVQGDLDAIFKDL-KVRSVRLVRDRETDKFKGFCYVEFEDLESLKEALEYDGALFEDRPLRV 77

RNA recognition motif 2 (RRM2) found in granule-associated RNA binding proteins (p40-TIA-1 and TIAR), and yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1; This subfamily corresponds to the RRM3 of TIA-1, TIAR, and PUB1. Nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR) are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. They share high sequence similarity and 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. This subfamily also includes a yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1, termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein, which has been identified as both a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP). It may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. PUB1 is distributed in both, the nucleus and the cytoplasm, and binds to poly(A)+ RNA (mRNA or pre-mRNA). Although it is one of the major cellular proteins cross-linked by UV light to polyadenylated RNAs in vivo, PUB1 is nonessential for cell growth in yeast. PUB1 also binds to T-rich single stranded DNA (ssDNA); however, there is no strong evidence implicating PUB1 in the mechanism of DNA replication. PUB1 contains three RRMs, and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDkfsghpKGYAYIEFASHRS-VKAAVGLDESTFRGRVIK 214
Cdd:cd12354   2 TVYVGNITKGLTEALLQQTFSPFGQILEVRVFPD------KGYAFIRFDSHEAaTHAIVSVNGTIINGQAVK 67

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein A/B (hnRNP A/B) and similar proteins; This subgroup corresponds to the RRM1 of hnRNP A/B, also termed APOBEC1-binding protein 1 (ABBP-1), which is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus plays an important role in apoB mRNA editing. hnRNP A/B contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long C-terminal glycine-rich domain that contains a potential ATP/GTP binding loop.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 55925591 139 EADHRSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKvlPK 218
Cdd:cd12757   1 EEDAGKMFVGGLSWDTSKKDLKDYFTKFGEVVDCTIKMDPNTGRSRGFGFILFKDAASVDKVLEQKEHRLDGRVID--PK 78

                .
gi 55925591 219 R 219
Cdd:cd12757  79 K 79

RNA recognition motif (RRM) found in ist3 family; This subfamily corresponds to the RRM of the ist3 family that includes fungal U2 small nuclear ribonucleoprotein (snRNP) component increased sodium tolerance protein 3 (ist3), X-linked 2 RNA-binding motif proteins (RBMX2) found in Metazoa and plants, and similar proteins. Gene IST3 encoding ist3, also termed U2 snRNP protein SNU17 (Snu17p), is a novel yeast Saccharomyces cerevisiae protein required for the first catalytic step of splicing and for progression of spliceosome assembly. It binds specifically to the U2 snRNP and is an intrinsic component of prespliceosomes and spliceosomes. Yeast ist3 contains an atypical RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). In the yeast pre-mRNA retention and splicing complex, the atypical RRM of ist3 functions as a scaffold that organizes the other two constituents, Bud13p (bud site selection 13) and Pml1p (pre-mRNA leakage 1). Fission yeast Schizosaccharomyces pombe gene cwf29 encoding ist3, also termed cell cycle control protein cwf29, is an RNA-binding protein complexed with cdc5 protein 29. It also contains one RRM. The biological function of RBMX2 remains unclear. It shows high sequence similarity to yeast ist3 protein and harbors one RRM as well.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12411  12 IYIGGLPYELTEGDILCVFSQYGEIVDINLVRDKKTGKSKGFAFLAYEDQRSTILAVdNLNGIKLLGRTIRV 83

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor SRSF2, SRSF8 and similar proteins; This subfamily corresponds to the RRM of SRSF2 and SRSF8. SRSF2, also termed protein PR264, or splicing component, 35 kDa (splicing factor SC35 or SC-35), is a prototypical SR protein that plays important roles in the alternative splicing of pre-mRNA. It is also involved in transcription elongation by directly or indirectly mediating the recruitment of elongation factors to the C-terminal domain of polymerase II. SRSF2 is exclusively localized in the nucleus and is restricted to nuclear processes. It contains a single N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by a C-terminal RS domain rich in serine-arginine dipeptides. The RRM is responsible for the specific recognition of 5'-SSNG-3' (S=C/G) RNA. In the regulation of alternative splicing events, it specifically binds to cis-regulatory elements on the pre-mRNA. The RS domain modulates SRSF2 activity through phosphorylation, directly contacts RNA, and promotes protein-protein interactions with the spliceosome. SRSF8, also termed SRP46 or SFRS2B, is a novel mammalian SR splicing factor encoded by a PR264/SC35 functional retropseudogene. SRSF8 is localized in the nucleus and does not display the same activity as PR264/SC35. It functions as an essential splicing factor in complementing a HeLa cell S100 extract deficient in SR proteins. Like SRSF2, SRSF8 contains a single N-terminal RRM and a C-terminal RS domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 55925591 147 VGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12311   3 VDNLTYRTTPDDLRRVFEKYGEVGDVYIPRDRYTRESRGFAFVRFYDKRDAEDAIdAMDGAELDGRELRV 72

RNA recognition motif 1 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM1 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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 144 SVFVGNVDYGGSAAELEAYFSPCGEIHRVTIlcdkFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12296   2 TVLVKNLPKSITENKIRQFFKDCGEIREVKI----LESGNGLVAVIEFETEDEALAALTKDHKRIGGNEISV 69

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein D-like (hnRNP D-like or hnRNP DL) and similar proteins; This subgroup corresponds to the RRM1 of hnRNP DL (or hnRNP D-like), also termed AU-rich element RNA-binding factor, or JKT41-binding protein (protein laAUF1 or JKTBP), which is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. hnRNP DL binds single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) in a non-sequencespecific manner, and interacts with poly(G) and poly(A) tenaciously. It contains two putative two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glycine- and tyrosine-rich C-terminus.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKvlPKR 219
Cdd:cd12758   2 MFIGGLSWDTSKKDLTEYLSRFGEVVDCTIKTDPVTGRSRGFGFVLFKDAASVDKVLELKEHKLDGKLID--PKR 74

RNA recognition motif (RRM) found in nuclear cap-binding protein subunit 2 (CBP20) and similar proteins; This subfamily corresponds to the RRM of CBP20, also termed nuclear cap-binding protein subunit 2 (NCBP2), or cell proliferation-inducing gene 55 protein, or NCBP-interacting protein 1 (NIP1). CBP20 is the small subunit of the nuclear cap binding complex (CBC), which is a conserved eukaryotic heterodimeric protein complex binding to 5'-capped polymerase II transcripts and plays a central role in the maturation of pre-mRNA and uracil-rich small nuclear RNA (U snRNA). CBP20 is most likely responsible for the binding of capped RNA. It contains an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and interacts with the second and third domains of CBP80, the large subunit of CBC.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVG-LDESTFRGRVIKV 215
Cdd:cd12240   1 LYVGNLSFYTTEEQIYELFSKCGDIKRIIMGLDKFKKTPCGFCFVEYYSREDAENAVKyLNGTKLDDRIIRV 72

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins; This subfamily corresponds to the RRM1 in hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins. hnRNP D0 is a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP A/B is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus plays an important role in apoB mRNA editing. hnRNP DL (or hnRNP D-like) is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. All members in this family contain two putative RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glycine- and tyrosine-rich C-terminus.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVI 213
Cdd:cd12575   1 MFIGGLSWDTSKKDLKDYFSKFGEVVDCTIKLDPVTGRSRGFGFVLFKDAESVDKVLDQKEHKLDGKVI 69

RNA recognition motif 2 (RRM2) found in yeast nuclear polyadenylated RNA-binding protein 4 (Hrp1p or Nab4p) and similar proteins; This subfamily corresponds to the RRM1 of Hrp1p and similar proteins. Hrp1p or Nab4p, also termed cleavage factor IB (CFIB), is a sequence-specific trans-acting factor that is essential for mRNA 3'-end formation in yeast Saccharomyces cerevisiae. It can be UV cross-linked to RNA and specifically recognizes the (UA)6 RNA element required for both, the cleavage and poly(A) addition steps. Moreover, Hrp1p can shuttle between the nucleus and the cytoplasm, and play an additional role in the export of mRNAs to the cytoplasm. Hrp1p also interacts with Rna15p and Rna14p, two components of CF1A. In addition, Hrp1p functions as a factor directly involved in modulating the activity of the nonsense-mediated mRNA decay (NMD) pathway; it binds specifically to a downstream sequence element (DSE)-containing RNA and interacts with Upf1p, a component of the surveillance complex, further triggering the NMD pathway. Hrp1p contains two central RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an arginine-glycine-rich region harboring repeats of the sequence RGGF/Y.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKV 215
Cdd:cd12330   2 IFVGGLAPDVTEEEFKEYFEQFGTVVDAVVMLDHDTGRSRGFGFVTFDSESAVEKVLSKGFHELGGKKVEV 72

RNA recognition motif 1 (RRM1) found in Arabidopsis thaliana CTC-interacting domain protein CID8, CID9, CID10, CID11, CID12, CID 13 and similar proteins; This subgroup corresponds to the RRM1 domains found in A. thaliana CID8, CID9, CID10, CID11, CID12, CID 13 and mainly their plant homologs. These highly related RNA-binding proteins contain an N-terminal PAM2 domain (PABP-interacting motif 2), two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a basic region that resembles a bipartite nuclear localization signal. The biological role of this family remains unclear.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDkfSGHPKGYAYIEFASHRSVKAAVGLDESTFRGRVIKVLPKRT 220
Cdd:cd12459   3 RTVYVSDIDQQVTEEQLAALFSNCGQVVDCRICGD--PNSVLRFAFIEFTDEEGARAALSLSGTMLGFYPVRVLPSKT 78

RNA recognition motif (RRM) found in cold inducible RNA binding protein (CIRBP), RNA binding motif protein 3 (RBM3) and similar proteins; This subfamily corresponds to the RRM domain of two structurally related heterogenous nuclear ribonucleoproteins, CIRBP (also termed CIRP or A18 hnRNP) and RBM3 (also termed RNPL), both of which belong to a highly conserved cold shock proteins family. The cold shock proteins can be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. CIRBP and RBM3 may function in posttranscriptional regulation of gene expression by binding to different transcripts, thus allowing the cell to response rapidly to environmental signals. However, the kinetics and degree of cold induction are different between CIRBP and RBM3. Tissue distribution of their expression is different. CIRBP and RBM3 may be differentially regulated under physiological and stress conditions and may play distinct roles in cold responses of cells. CIRBP, also termed glycine-rich RNA-binding protein CIRP, is localized in the nucleus and mediates the cold-induced suppression of cell cycle progression. CIRBP also binds DNA and possibly serves as a chaperone that assists in the folding/unfolding, assembly/disassembly and transport of various proteins. RBM3 may enhance global protein synthesis and the formation of active polysomes while reducing the levels of ribonucleoprotein complexes containing microRNAs. RBM3 may also serve to prevent the loss of muscle mass by its ability to decrease cell death. Furthermore, RBM3 may be essential for cell proliferation and mitosis. Both, CIRBP and RBM3, contain an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), that is involved in RNA binding, and C-terminal glycine-rich domain (RGG motif) that probably enhances RNA-binding via protein-protein and/or protein-RNA interactions. Like CIRBP, RBM3 can also bind to both RNA and DNA via its RRM domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12449   1 GKLFVGGLSFDTNEQSLEEVFSKYGQISEVVVVKDRETQRSRGFGFVTFENPDDAKDAMmAMNGKSLDGRQIRV 74

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 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFASHR-SVKAAVGLDESTFRGRVIKV 215
Cdd:cd12674   1 TTLFVRNLPFDVTLESLTDFFSDIGPVKHAVVVTDPETKKSRGYGFVSFSTHDdAEEALAKLKNRKLSGHILKL 74

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 55925591 145 VFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKfSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd12380   4 VYVKNFGEDVDDDELKELFEKYGKITSAKVMKDD-SGKSKGFGFVNFENHEAAQKAVeELNGKELNGKKLYV 74

RNA recognition motif 3 (RRM3) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM3 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
                ....*....|....*....|....*....|....*....|....*....|.
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTILCDKFSGHPKGYAYIEFAS 193
Cdd:cd12415   1 KTVFIRNLSFDTTEEDLKEFFSKFGEVKYARIVLDKDTGHSKGTAFVQFKT 51

RNA recognition motif 1 (RRM1) found in Schizosaccharomyces pombe mRNA export factor Crp79 and similar proteins; Crp79, also called meiotic expression up-regulated protein 5 (Mug5), or polyadenylate-binding protein crp79, or PABP, or poly(A)-binding protein, is an auxiliary mRNA export factor that binds the poly(A) tail of mRNA and is involved in the export of mRNA from the nucleus to the cytoplasm. 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 first RRM motif.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 55925591 143 RSVFVGNVDYGGSAAELEAYFSPCGEIHRVTI--LCDKFSGHPKGYAYIEFASHRSVKAAV-GLDESTFRGRVIKV 215
Cdd:cd21619   2 NTIYVGNIDMTINEDALEKIFSRYGQVESVRRppIHTDKADRTTGFGFIKYTDAESAERAMqQADGILLGRRRLVV 77