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 1831513154  64 RVYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12506     2 TVHMRGLPYRATENDIFEFFSPLNPVNVRIRYNKDGRATGEADVEFATHEDAVAAMSKDRENMGHRYIELFLN 74

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein hnRNP H protein family, G-rich sequence factor 1 (GRSF-1) and similar proteins; This subfamily corresponds to the RRM3 of hnRNP H proteins and GRSF-1. The hnRNP H protein family includes hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H'), hnRNP F and hnRNP H3 (also termed hnRNP 2H9), which represent a group of nuclear RNA binding proteins that are involved in pre-mRNA processing. These proteins have similar RNA binding affinities and specifically recognize the sequence GGGA. They can either stimulate or repress splicing upon binding to a GGG motif. hnRNP H binds to the RNA substrate in the presence or absence of these proteins, whereas hnRNP F binds to the nuclear mRNA only in the presence of cap-binding proteins. hnRNP H and hnRNP H2 are almost identical; both have been found to bind nuclear-matrix proteins. hnRNP H activates exon inclusion by binding G-rich intronic elements downstream of the 5' splice site in the transcripts of c-src, human immunodeficiency virus type 1 (HIV-1), Bcl-X, GRIN1, and myelin. It silences exons when bound to exonic elements in the transcripts of beta-tropomyosin, HIV-1, and alpha-tropomyosin. hnRNP H2 has been implicated in pre-mRNA 3' end formation. hnRNP H3 may be involved in the splicing arrest induced by heat shock. Most family members contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), except for hnRNP H3, in which the RRM1 is absent. RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and they play an important role in efficiently silencing the exon. For instance, members in this family can regulate the alternative splicing of the fibroblast growth factor receptor 2 (FGFR2) transcripts, and function as silencers of FGFR2 exon IIIc through an interaction with the exonic GGG motifs. The lack of RRM1 could account for the reduced silencing activity within hnRNP H3. In addition, the family members have an extensive glycine-rich region near the C-terminus, which may allow them to homo- or heterodimerize. The family also includes a cytoplasmic poly(A)+ mRNA binding protein, GRSF-1, which interacts with RNA in a G-rich element-dependent manner. It may function in RNA packaging, stabilization of RNA secondary structure, or other macromolecular interactions. GRSF-1 also contains three potential RRMs responsible for the RNA binding, and two auxiliary domains (an acidic alpha-helical domain and an N-terminal alanine-rich region) that may play a role in protein-protein interactions and provide binding specificity.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1831513154  64 RVYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12506     2 TVHMRGLPYRATENDIFEFFSPLNPVNVRIRYNKDGRATGEADVEFATHEDAVAAMSKDRENMGHRYIELFLN 74

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154   64 RVYMRGLPYDADDHAIAAFFSPL-RCHSVKIGIN-ETGRPSGDAIAEFDNYNDLQVALSRNNQRM--GRR 129
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFgKVESVRLVRDkETGKSKGFAFVEFESEEDAEKALEALNGKEldGRP 70

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein hnRNP H protein family, G-rich sequence factor 1 (GRSF-1) and similar proteins; This subfamily corresponds to the RRM3 of hnRNP H proteins and GRSF-1. The hnRNP H protein family includes hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H'), hnRNP F and hnRNP H3 (also termed hnRNP 2H9), which represent a group of nuclear RNA binding proteins that are involved in pre-mRNA processing. These proteins have similar RNA binding affinities and specifically recognize the sequence GGGA. They can either stimulate or repress splicing upon binding to a GGG motif. hnRNP H binds to the RNA substrate in the presence or absence of these proteins, whereas hnRNP F binds to the nuclear mRNA only in the presence of cap-binding proteins. hnRNP H and hnRNP H2 are almost identical; both have been found to bind nuclear-matrix proteins. hnRNP H activates exon inclusion by binding G-rich intronic elements downstream of the 5' splice site in the transcripts of c-src, human immunodeficiency virus type 1 (HIV-1), Bcl-X, GRIN1, and myelin. It silences exons when bound to exonic elements in the transcripts of beta-tropomyosin, HIV-1, and alpha-tropomyosin. hnRNP H2 has been implicated in pre-mRNA 3' end formation. hnRNP H3 may be involved in the splicing arrest induced by heat shock. Most family members contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), except for hnRNP H3, in which the RRM1 is absent. RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and they play an important role in efficiently silencing the exon. For instance, members in this family can regulate the alternative splicing of the fibroblast growth factor receptor 2 (FGFR2) transcripts, and function as silencers of FGFR2 exon IIIc through an interaction with the exonic GGG motifs. The lack of RRM1 could account for the reduced silencing activity within hnRNP H3. In addition, the family members have an extensive glycine-rich region near the C-terminus, which may allow them to homo- or heterodimerize. The family also includes a cytoplasmic poly(A)+ mRNA binding protein, GRSF-1, which interacts with RNA in a G-rich element-dependent manner. It may function in RNA packaging, stabilization of RNA secondary structure, or other macromolecular interactions. GRSF-1 also contains three potential RRMs responsible for the RNA binding, and two auxiliary domains (an acidic alpha-helical domain and an N-terminal alanine-rich region) that may play a role in protein-protein interactions and provide binding specificity.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1831513154  64 RVYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12506     2 TVHMRGLPYRATENDIFEFFSPLNPVNVRIRYNKDGRATGEADVEFATHEDAVAAMSKDRENMGHRYIELFLN 74

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein (hnRNP) H protein family, G-rich sequence factor 1 (GRSF-1) and similar proteins; This subfamily corresponds to the RRM1 of hnRNP H proteins and GRSF-1. The hnRNP H protein family includes hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H'), hnRNP F and hnRNP H3 (also termed hnRNP 2H9), which represent a group of nuclear RNA binding proteins that are involved in pre-mRNA processing. These proteins have similar RNA binding affinities and specifically recognize the sequence GGGA. They can either stimulate or repress splicing upon binding to a GGG motif. hnRNP H binds to the RNA substrate in the presence or absence of these proteins, whereas hnRNP F binds to the nuclear mRNA only in the presence of cap-binding proteins. hnRNP H and hnRNP H2 are almost identical; both have been found to bind nuclear-matrix proteins. hnRNP H activates exon inclusion by binding G-rich intronic elements downstream of the 5' splice site in the transcripts of c-src, human immunodeficiency virus type 1 (HIV-1), Bcl-X, GRIN1, and myelin. It silences exons when bound to exonic elements in the transcripts of beta-tropomyosin, HIV-1, and alpha-tropomyosin. hnRNP H2 has been implicated in pre-mRNA 3' end formation. hnRNP H3 may be involved in splicing arrest induced by heat shock. Most family members contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), except for hnRNP H3, in which the RRM1 is absent. RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and play an important role in efficiently silencing the exon. Members in this family can regulate the alternative splicing of fibroblast growth factor receptor 2 (FGFR2) transcripts, and function as silencers of FGFR2 exon IIIc through an interaction with the exonic GGG motifs. The lack of RRM1 could account for the reduced silencing activity within hnRNP H3. Members in this family have an extensive glycine-rich region near the C-terminus, which may allow them to homo- or heterodimerize. They also include a cytoplasmic poly(A)+ mRNA binding protein, GRSF-1, which interacts with RNA in a G-rich element-dependent manner. They may function in RNA packaging, stabilization of RNA secondary structure, or other macromolecular interactions. GRSF-1 contains three potential RRMs responsible for the RNA binding, and two auxiliary domains (an acidic alpha-helical domain and an N-terminal alanine-rich region) that may play a role in protein-protein interactions and provide binding specificity.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGINET----GRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFD 135
Cdd:cd12503     2 VRARGLPWSATAEDVLNFFTDCRIKGGENGIHFTytreGRPSGEAFIELESEEDVEKALEKHNEHMGHRYIEVFR 76

RNA recognition motif 2 (RRM2) found in RNA-binding protein 19 (RBM19) and similar proteins; This subfamily corresponds to the RRM2 of RBM19, also termed RNA-binding domain-1 (RBD-1), a nucleolar protein conserved in eukaryotes. It is involved in ribosome biogenesis by processing rRNA and is also essential for preimplantation development. RBM19 has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELF 134
Cdd:cd12502     3 VKLRGAPFNVKEKQIREFFSPLKPVAIRIVKNAHGNKTGYVFVDFKSEEDVEKALKRNKDYMGGRYIEVF 72

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein hnRNP H , hnRNP H2, hnRNP F and similar proteins; This subgroup corresponds to the RRM1 of hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H') and hnRNP F. These represent a group of nuclear RNA binding proteins that play important roles in the regulation of alternative splicing decisions. hnRNP H and hnRNP F are two closely related proteins, both of which bind to the RNA sequence DGGGD. They are present in a complex with the tissue-specific splicing factor Fox2, and regulate the alternative splicing of the fibroblast growth factor receptor 2 (FGFR2) transcripts. The presence of Fox 2 can allows hnRNP H and hnRNP F to better compete with the SR protein ASF/SF2 for binding to FGFR2 exon IIIc. Thus, hnRNP H and hnRNP F can function as potent silencers of FGFR2 exon IIIc inclusion through an interaction with the exonic GGG motifs. Furthermore, hnRNP H and hnRNP H2 are almost identical. Both of them have been found to bind nuclear-matrix proteins. hnRNP H activates exon inclusion by binding G-rich intronic elements downstream of the 5' splice site in the transcripts of c-src, human immunodeficiency virus type 1 (HIV-1), Bcl-X, GRIN1, and myelin. It silences exons when bound to exonic elements in the transcripts of beta-tropomyosin, HIV-1, and alpha-tropomyosin. hnRNP H2 has been implicated in pre-mRNA 3' end formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and they play an important role in efficiently silencing the exon. In addition, the family members have an extensive glycine-rich region near the C-terminus, which may allow them to homo- or heterodimerize.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGINET----GRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELF 134
Cdd:cd12729     4 VKVRGLPWSCSADEVQNFFSDCKIANGASGIHFIytreGRPSGEAFVELESEEDVKLALKKDRETMGHRYVEVF 77

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein hnRNP H , hnRNP H2, hnRNP F and similar proteins; This subgroup corresponds to the RRM3 of hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H') and hnRNP F, which represent a group of nuclear RNA binding proteins that play important roles in the regulation of alternative splicing decisions. hnRNP H and hnRNP F are two closely related proteins, both of which bind to the RNA sequence DGGGD. They are present in a complex with the tissue-specific splicing factor Fox2, and regulate the alternative splicing of the fibroblast growth factor receptor 2 (FGFR2) transcripts. The presence of Fox 2 can allows hnRNP H and hnRNP F to better compete with the SR protein ASF/SF2 for binding to FGFR2 exon IIIc. Thus, hnRNP H and hnRNP F can function as potent silencers of FGFR2 exon IIIc inclusion through an interaction with the exonic GGG motifs. Furthermore, hnRNP H and hnRNP H2 are almost identical; bothe have been found to bind nuclear-matrix proteins. hnRNP H activates exon inclusion by binding G-rich intronic elements downstream of the 5' splice site in the transcripts of c-src, human immunodeficiency virus type 1 (HIV-1), Bcl-X, GRIN1, and myelin. It silences exons when bound to exonic elements in the transcripts of beta-tropomyosin, HIV-1, and alpha-tropomyosin. hnRNP H2 has been implicated in pre-mRNA 3' end formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and they play an important role in efficiently silencing the exon. In addition, the family members have an extensive glycine-rich region near the C-terminus, which may allow them to homo- or heterodimerize.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12734     3 VHMRGLPYRATENDIYNFFSPLNPVRVHIEIGPDGRVTGEADVEFATHEDAVAAMSKDKANMQHRYVELFLN 74

RNA recognition motif 3 (RRM3) found in G-rich sequence factor 1 (GRSF-1) and similar proteins; This subgroup corresponds to the RRM3 of G-rich sequence factor 1 (GRSF-1), a cytoplasmic poly(A)+ mRNA binding protein which interacts with RNA in a G-rich element-dependent manner. It may function in RNA packaging, stabilization of RNA secondary structure, or other macromolecular interactions. GRSF-1 contains three potential RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), which are responsible for the RNA binding. In addition, GRSF-1 has two auxiliary domains, an acidic alpha-helical domain and an N-terminal alanine-rich region, that may play a role in protein-protein interactions and provide binding specificity.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12733     3 VHMRGLPFQANGQDIINFFAPLKPVRITMEYGPDGKATGEADVHFASHEDAVAAMAKDRSHMQHRYIELFLN 74

RNA recognition motif 1 (RRM1) found in epithelial splicing regulatory protein ESRP1, ESRP2, Drosophila RNA-binding protein Fusilli and similar proteins; This subfamily corresponds to the RRM1 of ESRPs and Fusilli. ESRP1 (also termed RBM35A) and ESRP2 (also termed RBM35B). These are epithelial-specific RNA binding proteins that promote splicing of the epithelial variant of the fibroblast growth factor receptor 2 (FGFR2), ENAH (also termed hMena), CD44 and CTNND1 (also termed p120-Catenin) transcripts. They are highly conserved paralogs and specifically bind to GU-rich binding site. ESRP1 and ESRP2 contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The family also includes Drosophila fusilli (fus) gene encoding RNA-binding protein Fusilli. Loss of fusilli activity causes lethality during embryogenesis in flies. Drosophila Fusilli can regulate endogenous fibroblast growth factor receptor 2 (FGFR2) splicing and functions as a splicing factor. It shows high sequence homology to ESRPs and contains three RRMs as well. It also has an N-terminal domain with unknown function and a C-terminal domain particularly rich in alanine, glutamine, and serine.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHS--VKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELF 134
Cdd:cd12507     2 VRARGLPWQSSDQDIAQFFRGLNIAKggVALCLSAQGRRNGEALIRFVDQEHRDLALQRHKHHMGTRYIEVY 73

RNA recognition motif (RRM) found in eukaryotic translation initiation factor 4B (eIF-4B) and similar proteins; This subfamily corresponds to the RRM of eIF-4B, a multi-domain RNA-binding protein that has been primarily implicated in promoting the binding of 40S ribosomal subunits to mRNA during translation initiation. It contains two RNA-binding domains; the N-terminal well-conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), binds the 18S rRNA of the 40S ribosomal subunit and the C-terminal basic domain (BD), including two arginine-rich motifs (ARMs), binds mRNA during initiation, and is primarily responsible for the stimulation of the helicase activity of eIF-4A. eIF-4B also contains a DRYG domain (a region rich in Asp, Arg, Tyr, and Gly amino acids) in the middle, which is responsible for both, self-association of eIF-4B and binding to the p170 subunit of eIF3. Additional research indicates that eIF-4B can interact with the poly(A) binding protein (PABP) in mammalian cells, which can stimulate both, the eIF-4B-mediated activation of the helicase activity of eIF-4A and binding of poly(A) by PABP. eIF-4B has also been shown to interact specifically with the internal ribosome entry sites (IRES) of several picornaviruses which facilitate cap-independent translation initiation.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1831513154  62 PLRVYMRGLPYDADDHAIAAFFSPLRCHSVKIGI-NETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRR 129
Cdd:cd12402     2 PYTAYLGNLPYDVTEDDIEDFFRGLNISSVRLPReNGPGRLRGFGYVEFEDRESLIQALSLNEESLKNR 70

RNA recognition motif 1 (RRM1) found in epithelial splicing regulatory protein 2 (ESRP2) and similar proteins; This subgroup corresponds to the RRM1 of ESRP2, also termed RNA-binding motif protein 35B (RBM35B), which has been identified as an epithelial cell type-specific regulator of fibroblast growth factor receptor 2 (FGFR2) splicing. It is required for expression of epithelial FGFR2-IIIb and the regulation of CD44, CTNND1 (also termed p120-Catenin) and ENAH (also termed hMena) splicing. It enhances epithelial-specific exons of CD44 and ENAH, silences mesenchymal exons of CTNND1, or both within FGFR2. ESRP2 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCH--SVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDNRG 138
Cdd:cd12737     2 IRARGLPWQSSDQDIARFFKGLNIAkgGVALCLNAQGRRNGEALVRFVNSEQRDLALERHKHHMGSRYIEVYKATG 77

RNA recognition motif 2 (RRM2) found in RNA-binding protein 12 (RBM12) and similar proteins; This subgroup corresponds to the RRM2 of RBM12, also termed SH3/WW domain anchor protein in the nucleus (SWAN), which is ubiquitously expressed. It contains five distinct RNA binding motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), two proline-rich regions, and several putative transmembrane domains. The biological role of RBM12 remains unclear.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1831513154  63 LRVYMRGLPYDADDHAIAAFFSPLRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELF 134
Cdd:cd12747     2 LYVHLHGMPFSATEADVRDFFHGLRIDAIHMLKDHLGRNNGNALVKFYSPQDTFEALKRNRMMMGQRYIEVS 73

RNA recognition motif 1 (RRM1) found in epithelial splicing regulatory protein 1 (ESRP1) and similar proteins; This subgroup corresponds to the RRM1 of ESRP1, also termed RNA-binding motif protein 35A (RBM35A), which has been identified as an epithelial cell type-specific regulator of fibroblast growth factor receptor 2 (FGFR2) splicing. It is required for expression of epithelial FGFR2-IIIb and the regulation of CD44, CTNND1 (p120-Catenin) and ENAH (hMena) splicing. It enhances epithelial-specific exons of CD44 and ENAH, silences mesenchymal exons of CTNND1, or both within FGFR2. Additional research indicated that ESRP1 functions as a tumor suppressor in colon cancer cells. It may be involved in posttranscriptional regulation of various genes by exerting a differential effect on protein translation via 5' untranslated regions (UTRs) of mRNAs. ESRP1 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  60 DDPLRVYMRGLPYDADDHAIAAFFSPLRCHS--VKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDNR 137
Cdd:cd12736     7 DDNTVIRARGLPWQSSDQDIARFFKGLNIAKggAALCLNAQGRRNGEALVRFVNEEHRDLALQRHKHHMGNRYIEVYKAT 86

                  .
gi 1831513154 138 G 138
Cdd:cd12736    87 G 87

RNA recognition motif 3 (RRM3) found in epithelial splicing regulatory protein ESRP1, ESRP2 and similar proteins; This subgroup corresponds to the RRM3 of ESRP1 (also termed RBM35A) and ESRP2 (also termed RBM35B). These are epithelial-specific RNA binding proteins that promote splicing of the epithelial variant of the fibroblast growth factor receptor 2 (FGFR2), ENAH (also termed hMena), CD44 and CTNND1 (also termed p120-Catenin) transcripts. They are highly conserved paralogs and specifically bind to GU-rich binding site. ESRP1 and ESRP2 contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSP----LRCHSVKIGINETGRPSGDAIAEFDNYND-LQVALSRNNQRMGRRYVELF 134
Cdd:cd12742     4 IRLRGLPYAATIEDILEFLGEfaadIRPHGVHMVLNHQGRPSGDAFIQMKSADRaFLAAQKCHKKTMKDRYVEVF 78

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein H3 (hnRNP H3) and similar proteins; This subgroup corresponds to the RRM2 of hnRNP H3 (also termed hnRNP 2H9), a nuclear RNA binding protein that belongs to the hnRNP H protein family that also includes hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H') and hnRNP F. This family is involved in mRNA processing and exhibit extensive sequence homology. Currently, little is known about the functions of hnRNP H3 except for its role in the splicing arrest induced by heat shock. In addition, the typical hnRNP H proteins contain contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), except for hnRNP H3, in which the RRM1 is absent. RRM1 and RRM2 are responsible for the binding to the RNA at DGGGD motifs, and play an important role in efficiently silencing the exon. Members in this family can regulate the alternative splicing of the fibroblast growth factor receptor 2 (FGFR2) transcripts, and function as silencers of FGFR2 exon IIIc through an interaction with the exonic GGG motifs. The lack of RRM1 could account for the reduced silencing activity within hnRNP H3. In addition, like other hnRNP H protein family members, hnRNP H3 has an extensive glycine-rich region near the C-terminus, which may allow it to homo- or heterodimerize.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  51 GRSDYGRGGDDPLRvyMRGLPYDADDHAIAAFFSPLRC--HSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGR 128
Cdd:cd12732     9 GPTDTENSSDGTVR--LRGLPFGCSKEEIVQFFSGLEIvpNGITLTMDYQGRSTGEAFVQFASKEIAENALGKHKERIGH 86

                  ....*.
gi 1831513154 129 RYVELF 134
Cdd:cd12732    87 RYIEIF 92

RNA recognition motif 2 (RRM2) found in epithelial splicing regulatory protein 2 (ESRP2) and similar proteins; This subgroup corresponds to the RRM2 of ESRP2, also termed RNA-binding motif protein 35B (RBM35B), which has been identified as an epithelial cell type-specific regulator of fibroblast growth factor receptor 2 (FGFR2) splicing. It is required for expression of epithelial FGFR2-IIIb and the regulation of CD44, CTNND1 (also termed p120-Catenin) and ENAH (also termed hMena) splicing. It enhances epithelial-specific exons of CD44 and ENAH, silences mesenchymal exons of CTNND1, or both within FGFR2. ESRP2 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  60 DDPLRVYMRGLPYDADDHAIAAFFSPlRChSVKIGIN-------ETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVE 132
Cdd:cd12740    14 ENQVIIRMRGLPFTATPEDVLGFLGP-EC-PVTGGTEgllfvkyPDGRPTGDAFVLFACEEYAQNALKKHKGILGKRYIE 91

                  ....*..
gi 1831513154 133 LFDNRGA 139
Cdd:cd12740    92 LFRSTAA 98

RNA recognition motif 5 (RRM5) found in RNA-binding protein 12B (RBM12B) and similar proteins; This subgroup corresponds to the RRM5 of RBM12B which contains five distinct RNA binding motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). Its biological role remains unclear.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRC--HSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQR-MGRRYVEL 133
Cdd:cd12750     3 VKLFNLPFKATVNEILDFFYGYRVipDSVSIQYNEQGLPTGDAIIAMETYEEAMAAVQDLNDRpIGPRKVKL 74

RNA recognition motif 2 (RRM2) found in epithelial splicing regulatory protein 1 (ESRP1) and similar proteins; This subgroup corresponds to the RRM2 of ESRP1, also termed RNA-binding motif protein 35A (RBM35A), which has been identified as an epithelial cell type-specific regulator of fibroblast growth factor receptor 2 (FGFR2) splicing. It is required for expression of epithelial FGFR2-IIIb and the regulation of CD44, CTNND1 (also termed p120-Catenin) and ENAH (also termed hMena) splicing. It enhances epithelial-specific exons of CD44 and ENAH, silences mesenchymal exons of CTNND1, or both within FGFR2. Additional research indicated that ESRP1 functions as a tumor suppressor in colon cancer cells. It may be involved in posttranscriptional regulation of various genes by exerting a differential effect on protein translation via 5' untranslated regions (UTRs) of mRNAs. ESRP1 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPlrcHSVKIGINE--------TGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYVELFDN 136
Cdd:cd12739    19 VRMRGLPFTATAEEVLAFFGQ---HCPVTGGKEgilfvtypDSRPTGDAFVLFACEEYAQNALKKHKDLLGKRYIELFRS 95

                  ...
gi 1831513154 137 RGA 139
Cdd:cd12739    96 TAA 98

RNA recognition motif 4 (RRM4) found in RNA-binding protein RBM12, RBM12B and similar proteins; This subfamily corresponds to the RRM4 of RBM12 and RBM12B. RBM12, also termed SH3/WW domain anchor protein in the nucleus (SWAN), is ubiquitously expressed. It contains five distinct RNA binding motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), two proline-rich regions, and several putative transmembrane domains. RBM12B show high sequence semilarity with RBM12. It contains five distinct RRMs as well. The biological roles of both RBM12 and RBM12B remain unclear.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1831513154  64 RVYMRGLPYDADDHAIAAFFSP--LRCHSVKIGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRYV 131
Cdd:cd12514     1 FIRITNLPYDATPVDIQRFFEDhgVRPEDVHLLRNKKGRGNGEALVTFKSEGDAREVLKLNGKKLGKREA 70

RNA recognition motif 3 (RRM3) found in Drosophila RNA-binding protein Fusilli and similar proteins; This subgroup corresponds to the RRM3 of RNA-binding protein Fusilli which is encoded by Drosophila fusilli (fus) gene. Loss of Fusilli activity causes lethality during embryogenesis in flies. Drosophila Fusilli can regulate endogenous fibroblast growth factor receptor 2 (FGFR2) splicing and functions as a splicing factor. Fusilli contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), an N-terminal domain with unknown function and a C-terminal domain particularly rich in alanine, glutamine, and serine.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1831513154  65 VYMRGLPYDADDHAIAAFFSPLRCHSVKIGI----NETGRPSGDAIAEFDN-YNDLQVALSRNNQRM----GRRYVELF 134
Cdd:cd12743     4 IRLRGLPYEAQVEHILEFLGDFAKMIVFQGVhmvyNAQGQPSGEAFIQMDSeQSASACAQQRHNRYMvfgkKQRYIEVF 82

RNA recognition motif 1 (RRM1) found in Arabidopsis thaliana phragmoplastin interacting protein 1 (PHIP1) and similar proteins; This subfamily corresponds to the RRM1 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 1831513154  65 VYMRGLPYDADDHAIAAFFSplRCHSVK----IGINETGRPSGDAIAEFDNYNDLQVALSRNNQRMGRRY 130
Cdd:cd12271     1 VYVGGIPYYSTEAEIRSYFS--SCGEVRsvdlMRFPDSGNFRGIAFITFKTEEAAKRALALDGEMLGNRF 68

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1831513154  64 RVYMRGLPYDADDHAIAAFFSPL-RCHSVKIgINETGRPSGDAIAEFDNYNDLQVALSRNNQR--MGR 128
Cdd:cd21605     3 SIFVGNLPFDCTWEDLKDHFSQVgEVIRADI-VTSRGRHRGMGTVEFTNKEDVDRAISKFDHTmfMGR 69