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).

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gi 767918083  12 GYLIHVGGLCPSVSEADLRSHFQKYQVSEISIYD-STNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNVWPVKIL 87
Cdd:cd12248    1 CVYVHVGNLAPSVSEEDLLMHFEKYHVSKISIQKlSMNYRYASLTFDDASDAQAAVKEMNGKDISGRKVKVRYVKES 77

RNA recognition motif (RRM) found in RNA-binding protein 44 (RBM44) and similar proteins; This subgroup corresponds to the RRM of RBM44, a novel germ cell intercellular bridge protein that is localized in the cytoplasm and intercellular bridges from pachytene to secondary spermatocyte stages. RBM44 interacts with itself and testis-expressed gene 14 (TEX14). Unlike TEX14, RBM44 does not function in the formation of stable intercellular bridges. It carries an RNA recognition motif (RRM) that could potentially bind a multitude of RNA sequences in the cytoplasm and help to shuttle them through the intercellular bridge, facilitating their dispersion into the interconnected neighboring cells.

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gi 767918083  12 GYLIHVGGLCPSVSEADLRSHFQKYQVSEISIYD-STNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNVWPVKIL 87
Cdd:cd12248    1 CVYVHVGNLAPSVSEEDLLMHFEKYHVSKISIQKlSMNYRYASLTFDDASDAQAAVKEMNGKDISGRKVKVRYVKES 77

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

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gi 767918083   15 IHVGGLCPSVSEADLRSHFQKY-QVSEISI-YDST--NYRYASLAFTKNSDAKIAVKEMNGIEINGKSV 79
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFgPIKSIRLvRDETgrSKGFAFVEFEDEEDAEKAIEALNGKELGGREL 69

RNA recognition motif (RRM) found in RNA-binding protein 44 (RBM44) and similar proteins; This subgroup corresponds to the RRM of RBM44, a novel germ cell intercellular bridge protein that is localized in the cytoplasm and intercellular bridges from pachytene to secondary spermatocyte stages. RBM44 interacts with itself and testis-expressed gene 14 (TEX14). Unlike TEX14, RBM44 does not function in the formation of stable intercellular bridges. It carries an RNA recognition motif (RRM) that could potentially bind a multitude of RNA sequences in the cytoplasm and help to shuttle them through the intercellular bridge, facilitating their dispersion into the interconnected neighboring cells.

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gi 767918083  12 GYLIHVGGLCPSVSEADLRSHFQKYQVSEISIYD-STNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNVWPVKIL 87
Cdd:cd12248    1 CVYVHVGNLAPSVSEEDLLMHFEKYHVSKISIQKlSMNYRYASLTFDDASDAQAAVKEMNGKDISGRKVKVRYVKES 77

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.

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEIS-IYDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd21608    2 LYVGNLSWDTTEDDLRDLFSEFgEVESAKvITDRETGRsrgFGFVTFSTAEAAEAAIDALNGKELDGRSIVV 73

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

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gi 767918083   15 IHVGGLCPSVSEADLRSHFQKY-QVSEISI-YDST--NYRYASLAFTKNSDAKIAVKEMNGIEINGKSV 79
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFgPIKSIRLvRDETgrSKGFAFVEFEDEEDAEKAIEALNGKELGGREL 69

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.

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEIS-IYDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12382    4 LFIGGLNTETNEKALEAVFGKYgRIVEVLlMKDRETNKsrgFAFVTFESPADAKDAARDMNGKELDGKAIKV 75

RNA recognition motif 2 (RRM2) found in Deleted in azoospermia-associated protein 1 (DAZAP1) and similar proteins; This subfamily corresponds to the RRM2 of DAZAP1 or DAZ-associated protein 1, also termed proline-rich RNA binding protein (Prrp), a multi-functional ubiquitous RNA-binding protein expressed most abundantly in the testis and essential for normal cell growth, development, and spermatogenesis. DAZAP1 is a shuttling protein whose acetylated is predominantly nuclear and the nonacetylated form is in cytoplasm. DAZAP1 also functions as a translational regulator that activates translation in an mRNA-specific manner. DAZAP1 was initially identified as a binding partner of Deleted in Azoospermia (DAZ). It also interacts with numerous hnRNPs, including hnRNP U, hnRNP U like-1, hnRNPA1, hnRNPA/B, and hnRNP D, suggesting DAZAP1 might associate and cooperate with hnRNP particles to regulate adenylate-uridylate-rich elements (AU-rich element or ARE)-containing mRNAs. DAZAP1 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal proline-rich domain.

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gi 767918083  11 KGYLIHVGGLCPSVSEADLRSHFQKY-QVSEIS-IYDSTNYR---YASLAFTKNSDAKIAVKeMNGIEINGKSVNV 81
Cdd:cd12327    1 KSKKVFVGGIPHNCGETELRDYFKRYgVVTEVVmMYDAEKQRsrgFGFITFEDEQSVDQAVN-MHFHDIMGKKVEV 75

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.

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEISIYDSTNyrYASLAFTKNSDAKIAVKEMNGIEINGKSV 79
Cdd:cd12354    3 VYVGNITKGLTEALLQQTFSPFgQILEVRVFPDKG--YAFIRFDSHEAATHAIVSVNGTIINGQAV 66

RNA recognition motif 2 (RRM2) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM2 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

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gi 767918083  20 LCPSVSEADLRSHFQKY-QVSEISI---YDSTNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNV-WPV 84
Cdd:cd12414    7 LPFKCTEDDLKKLFSKFgKVLEVTIpkkPDGKLRGFAFVQFTNVADAAKAIKGMNGKKIKGRPVAVdWAV 76

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.

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gi 767918083  17 VGGLCPSVSEADLRSHFQKY-QVSEIS-IYDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12449    5 VGGLSFDTNEQSLEEVFSKYgQISEVVvVKDRETQRsrgFGFVTFENPDDAKDAMMAMNGKSLDGRQIRV 74

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.

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKYQ--VSEISIYDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12447    2 LFVGGLSWNVDDPWLKKEFEKYGgvISARVITDRGSGRskgYGYVDFATPEAAQKALAAMSGKEIDGRQINV 73

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

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQK-YQVSEISI-YDSTNYRY--ASLAFTKNSDAKIAVKEMNGIEINGK 77
Cdd:cd12418    3 VRVSNLHPDVTEEDLRELFGRvGPVKSVKInYDRSGRSTgtAYVVFERPEDAEKAIKQFDGVLLDGQ 69

RNA recognition motif 1 (RRM1) found in Saccharomyces cerevisiae protein PES4, protein MIP6 and similar proteins; The family includes PES4 (also called DNA polymerase epsilon suppressor 4) and MIP6 (also called MEX67-interacting protein 6), both of which are predicted RNA binding proteins that may act as regulators of late translation, protection, and mRNA localization. MIP6 acts as a novel factor for nuclear mRNA export, binds to both poly(A)+ RNA and nuclear pores. It interacts with MEX67. Members in this family contain four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the first RRM motif.

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gi 767918083  17 VGGLCPSVSEADLRSHFQKYQvSEISI---YDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNVWP 83
Cdd:cd21601    5 IGDLDKDVTEEMLRDIFSKYK-SLVSVkicLDSETKKslgYGYLNFSDKEDAEKAIEEFNYTPIFGKEVRIMP 76

RNA recognition motif 3 (RRM3) found in SMART/HDAC1-associated repressor protein (SHARP) and similar proteins; This subfamily corresponds to the RRM3 of SHARP, also termed Msx2-interacting protein (MINT), or SPEN homolog, an estrogen-inducible transcriptional repressor that interacts directly with the nuclear receptor corepressor SMRT, histone deacetylases (HDACs) and components of the NuRD complex. SHARP recruits HDAC activity and binds to the steroid receptor RNA coactivator SRA through four conserved N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), further suppressing SRA-potentiated steroid receptor transcription activity. Thus, SHARP has the capacity to modulate both liganded and nonliganded nuclear receptors. SHARP also has been identified as a component of transcriptional repression complexes in Notch/RBP-Jkappa signaling pathways. In addition to the N-terminal RRMs, SHARP possesses a C-terminal SPOC domain (Spen paralog and ortholog C-terminal domain), which is highly conserved among Spen proteins.

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gi 767918083  17 VGGLCPSVSEADLRSHFQKY-QVSEISI-YDSTNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12350    7 IGNLEKTTTYGDLRNIFERFgEIIDIDIkKQNGNPQYAFLQYCDIASVVKAIKKMDGEYLGNNRLKL 73

RNA recognition motif 1 (RRM1) found in the p54nrb/PSF/PSP1 family; This subfamily corresponds to the RRM1 of the p54nrb/PSF/PSP1 family, including 54 kDa nuclear RNA- and DNA-binding protein (p54nrb or NonO or NMT55), polypyrimidine tract-binding protein (PTB)-associated-splicing factor (PSF or POMp100), paraspeckle protein 1 (PSP1 or PSPC1), which are ubiquitously expressed and are conserved in vertebrates. p54nrb is a multi-functional protein involved in numerous nuclear processes including transcriptional regulation, splicing, DNA unwinding, nuclear retention of hyperedited double-stranded RNA, viral RNA processing, control of cell proliferation, and circadian rhythm maintenance. PSF is also a multi-functional protein that binds RNA, single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and many factors, and mediates diverse activities in the cell. PSP1 is a novel nucleolar factor that accumulates within a new nucleoplasmic compartment, termed paraspeckles, and diffusely distributes in the nucleoplasm. The cellular function of PSP1 remains unknown currently. This subfamily also includes some p54nrb/PSF/PSP1 homologs from invertebrate species, such as the Drosophila melanogaster gene no-ontransient A (nonA) encoding puff-specific protein Bj6 (also termed NONA) and Chironomus tentans hrp65 gene encoding protein Hrp65. D. melanogaster NONA is involved in eye development and behavior, and may play a role in circadian rhythm maintenance, similar to vertebrate p54nrb. C. tentans Hrp65 is a component of nuclear fibers associated with ribonucleoprotein particles in transit from the gene to the nuclear pore. All family members contain a DBHS domain (for Drosophila behavior, human splicing), which comprises two conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a charged protein-protein interaction module. PSF has an additional large N-terminal domain that differentiates it from other family members.

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gi 767918083  17 VGGLCPSVSEADLRSHFQKY-QVSEISIYDSTNYRYASLAFTKNsdAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12332    6 VGNLPNDITEEEFKELFQKYgEVSEVFLNKGKGFGFIRLDTRAN--AEAAKAELDGTPRKGRQLRV 69

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.

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gi 767918083  17 VGGLCPSVSEADLRSHFQKY-QVSEISI-YDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12236    6 VARLSYDTTESKLRREFEKYgPIKRVRLvRDKKTGKsrgYAFIEFEHERDMKAAYKHADGKKIDGRRVLV 75

RNA recognition motif 2 (RRM2) found in yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1 and similar proteins; This subgroup corresponds to the RRM2 of yeast protein PUB1, also termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein. PUB1 has been identified as both, a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP), which may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. It 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 RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

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gi 767918083  12 GYLIHVGGLCPSVSEADLRSHFQKY-QVSEISI-YDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNV-WPVK 85
Cdd:cd12619    1 HFNIFVGDLSPEVTDAALFNAFSDFpSCSDARVmWDQKTGRsrgYGFVSFRSQQDAQNAINSMNGKWLGSRPIRCnWATK 80

RNA recognition motif 1 (RRM1) found in serine/arginine-rich splicing factor 4 (SRSF4) and similar proteins; This subfamily corresponds to the RRM1 in three serine/arginine (SR) proteins: serine/arginine-rich splicing factor 4 (SRSF4 or SRp75 or SFRS4), serine/arginine-rich splicing factor 5 (SRSF5 or SRp40 or SFRS5 or HRS), serine/arginine-rich splicing factor 6 (SRSF6 or SRp55). SRSF4 plays an important role in both, constitutive and alternative, splicing of many pre-mRNAs. It can shuttle between the nucleus and cytoplasm. SRSF5 regulates both alternative splicing and basal splicing. It is the only SR protein efficiently selected from nuclear extracts (NE) by the splicing enhancer (ESE) and essential for enhancer activation. SRSF6 preferentially interacts with a number of purine-rich splicing enhancers (ESEs) to activate splicing of the ESE-containing exon. It is the only protein from HeLa nuclear extract or purified SR proteins that specifically binds B element RNA after UV irradiation. SRSF6 may also recognize different types of RNA sites. Members in this family contain two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal RS domains rich in serine-arginine dipeptides.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEISIYDStnyrYASLAFTKNSDAKIAVKEMNGIEINGKSVNVWPVK 85
Cdd:cd12337    2 VYIGRLPYRARERDVERFFRGYgRIRDINLKNG----FGFVEFEDPRDADDAVYELNGKELCGERVIVEHAR 69

RNA recognition motif 4 (RRM4) found in SMART/HDAC1-associated repressor protein (SHARP) and similar proteins; This subfamily corresponds to the RRM of SHARP, also termed Msx2-interacting protein (MINT), or SPEN homolog, is an estrogen-inducible transcriptional repressor that interacts directly with the nuclear receptor corepressor SMRT, histone deacetylases (HDACs) and components of the NuRD complex. SHARP recruits HDAC activity and binds to the steroid receptor RNA coactivator SRA through four conserved N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), further suppressing SRA-potentiated steroid receptor transcription activity. Thus, SHARP has the capacity to modulate both liganded and nonliganded nuclear receptors. SHARP also has been identified as a component of transcriptional repression complexes in Notch/RBP-Jkappa signaling pathways. In addition to the N-terminal RRMs, SHARP possesses a C-terminal SPOC domain (Spen paralog and ortholog C-terminal domain), which is highly conserved among Spen proteins.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767918083  19 GLCPSVSEADLRSHFQKY-QVSEISIydsTNYRYASLAFTKNSD-AKIAVKEMNGIEINGKSVNV 81
Cdd:cd12351   14 GLSENVTEQYLTRHFCRYgPVVKVVI---DRQKGMALVLYDEVEcAQAAVKETKGRKIGGRKIQV 75

RNA recognition motif 2 (RRM2) found in vertebrate RNA-binding protein RBM23, RBM39 and similar proteins; This subfamily corresponds to the RRM2 of RBM39 (also termed HCC1), a nuclear autoantigen that contains an N-terminal arginine/serine rich (RS) motif and three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). An octapeptide sequence called the RS-ERK motif is repeated six times in the RS region of RBM39. Although the cellular function of RBM23 remains unclear, it shows high sequence homology to RBM39 and contains two RRMs. It may possibly function as a pre-mRNA splicing factor.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEISI-YDSTNYR---YASLAFTKNSDAKIAVKEMNGIEINGKSVNVWPV 84
Cdd:cd12284    1 LYVGSLHFNITEDMLRGIFEPFgKIEFVQLqKDPETGRskgYGFIQFRDAEDAKKALEQLNGFELAGRPMKVGHV 75

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

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEISIYDStnyrYASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12607    3 LHVGNISSSCTNQELRAKFEEYgPVIECDIVKD----YAFVHMERAEDAMEAIRGLDNTEFQGKRMHV 66

RNA recognition motif 2 (RRM2) found in yeast regulator of rDNA transcription protein 5 (RRT5) and similar proteins; This subfamily corresponds to the RRM2 of the lineage specific family containing a group of uncharacterized yeast regulators of rDNA transcription protein 5 (RRT5), which may play roles in the modulation of rDNA transcription. RRT5 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKYQVSEISIYDSTNYRYASLAFTKNSDA-----------KIAVKEMNGIEINGKSVNVWP 83
Cdd:cd12410    5 VYIGNLPGNTTDNDLREFFKDYNPQEIWIFRTKKSRRNPMYLHRHFTAalvtlpdeerlDEAIESLKSKKLNGKKISLKP 84

RNA recognition motif (RRM) found in eukaryotic RNA-binding protein RBM24, RBM38 and similar proteins; This subfamily corresponds to the RRM of RBM24 and RBM38 from vertebrate, SUPpressor family member SUP-12 from Caenorhabditis elegans and similar proteins. Both, RBM24 and RBM38, are preferentially expressed in cardiac and skeletal muscle tissues. They regulate myogenic differentiation by controlling the cell cycle in a p21-dependent or -independent manner. RBM24, also termed RNA-binding region-containing protein 6, interacts with the 3'-untranslated region (UTR) of myogenin mRNA and regulates its stability in C2C12 cells. RBM38, also termed CLL-associated antigen KW-5, or HSRNASEB, or RNA-binding region-containing protein 1(RNPC1), or ssDNA-binding protein SEB4, is a direct target of the p53 family. It is required for maintaining the stability of the basal and stress-induced p21 mRNA by binding to their 3'-UTRs. It also binds the AU-/U-rich elements in p63 3'-UTR and regulates p63 mRNA stability and activity. SUP-12 is a novel tissue-specific splicing factor that controls muscle-specific splicing of the ADF/cofilin pre-mRNA in C. elegans. All family members contain a conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSE-ISIYDSTNYR---YASLAFTKNSDAKIAVKEMNGIeINGKSVNV 81
Cdd:cd12384    3 IFVGGLPYHTTDDSLREYFEQFgEIEEaVVITDRQTGKsrgYGFVTMADREAAERACKDPNPI-IDGRKANV 73

RNA recognition motif 2 (RRM2) found in TAR DNA-binding protein 43 (TDP-43) and similar proteins; This subfamily corresponds to the RRM2 of TDP-43 (also termed TARDBP), a ubiquitously expressed pathogenic protein whose normal function and abnormal aggregation are directly linked to the genetic disease cystic fibrosis, and two neurodegenerative disorders: frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). TDP-43 binds both DNA and RNA, and has been implicated in transcriptional repression, pre-mRNA splicing and translational regulation. TDP-43 is a dimeric protein with two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal glycine-rich domain. The RRMs are responsible for DNA and RNA binding; they bind to TAR DNA and RNA sequences with UG-repeats. The glycine-rich domain can interact with the hnRNP family proteins to form the hnRNP-rich complex involved in splicing inhibition. It is also essential for the cystic fibrosis transmembrane conductance regulator (CFTR) exon 9-skipping activity.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKYqvSEIS-IYDSTNYRyaSLAFTKNSDAKIAVKEM-NGIEINGKSVNV 81
Cdd:cd12322    3 VFVGRCTEDMTEDDLRQYFSQF--GEVTdVFIPKPFR--AFAFVTFADDEVAQSLCgEDHIIKGVSVHI 67

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

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gi 767918083  17 VGGLCPSVSEADLRSHFQkyQVSEISIYDSTNYR--YASLAFTKNSDAKIAVKEMNGIEINGKSVNV 81
Cdd:cd12339    5 VSNLPERASWQDLKDFMR--KAGEVTYADVHRDRegEGVVEFTSEEDMKRAIEKLDGTEFNGRRIRV 69

RNA recognition motif 1 (RRM1) found in granule-associated RNA binding proteins p40-TIA-1 and TIAR; This subfamily corresponds to the RRM1 of nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR), both of which are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. TIA-1 and TIAR share high sequence similarity. They are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis.TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both, TIA-1 and TIAR, bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains.

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gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY---QVSEISIYDSTNYRYASLAFTKNSDAKIAVKEMNGIEINGKSVNV-W 82
Cdd:cd12352    1 LYVGNLDRQVTEDLILQLFSQIgpcKSCKMITEHGGNDPYCFVEFYEHNHAAAALQAMNGRKILGKEVKVnW 72

RNA recognition motif (RRM) found in U2-associated protein SR140 and similar proteins; This subgroup corresponds to the RRM of SR140 (also termed U2 snRNP-associated SURP motif-containing protein orU2SURP, or 140 kDa Ser/Arg-rich domain protein) which is a putative splicing factor mainly found in higher eukaryotes. Although it is initially identified as one of the 17S U2 snRNP-associated proteins, the molecular and physiological function of SR140 remains unclear. SR140 contains an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a SWAP/SURP domain that is found in a number of pre-mRNA splicing factors in the middle region, and a C-terminal arginine/serine-rich domain (RS domain).

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767918083  15 IHVGGLCPSVSEADLRSHFQKY-QVSEISIY----DSTNYRYAS---LAFTKNSDAKIAVKEMNGIEING 76
Cdd:cd12223    4 LYVGNLPPSVTEEVLLREFGRFgPLASVKIMwprtEEERRRNRNcgfVAFMSRADAERAMRELNGKDVMG 73