RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545    11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVRDKEtGKSKGFAFVEFESEEDAEKALEALNGKELDGRPLKV 73

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:COG0724    3 KIYVGNLPYSVTEEDLRELFSEYGEVTSVKLITDREtGRSRGFGFVEMPDDEEAQAAIEALNGAELMGRTLKV 75

glycine-rich RNA-binding protein 4; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQFRSGSSH 90
Cdd:PLN03134  37 LFIGGLSWGTDDASLRDAFAHFGDVVDAKVIVDREtGRSRGFGFVNFNDEGAATAAISEMDGKELNGRHIRVNPANDRPS 116

                 ...
gi 554506545  91 APQ 93
Cdd:PLN03134 117 APR 119

RNA recognition motif (RRM) found in RNA-binding protein 7 (RBM7) and similar proteins; This subfamily corresponds to the RRM of RBM7, RBM11 and their eukaryotic homologous. RBM7 is an ubiquitously expressed pre-mRNA splicing factor that enhances messenger RNA (mRNA) splicing in a cell-specific manner or in a certain developmental process, such as spermatogenesis. It interacts with splicing factors SAP145 (the spliceosomal splicing factor 3b subunit 2) and SRp20, and may play a more specific role in meiosis entry and progression. Together with additional testis-specific RNA-binding proteins, RBM7 may regulate the splicing of specific pre-mRNA species that are important in the meiotic cell cycle. RBM11 is a novel tissue-specific splicing regulator that is selectively expressed in brain, cerebellum and testis, and to a lower extent in kidney. It is localized in the nucleoplasm and enriched in SRSF2-containing splicing speckles. It may play a role in the modulation of alternative splicing during neuron and germ cell differentiation. Both, RBM7 and RBM11, contain an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a region lacking known homology at the C-terminus. The RRM is responsible for RNA binding, whereas the C-terminal region permits nuclear localization and homodimerization.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506545   9 DRTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQ 83
Cdd:cd12336    1 DRTLFVGNLDPRVTEEILYELFLQAGPLEGVKIPKDPNGKPKNFAFVTFKHEVSVPYAIQLLNGIRLFGREIRIK 75

RNA recognition motif 1 (RRM1) found in splicing factor 3B subunit 4 (SF3B4) and similar proteins; This subfamily corresponds to the RRM1 of SF3B4, also termed pre-mRNA-splicing factor SF3b 49 kDa (SF3b50), or spliceosome-associated protein 49 (SAP 49). SF3B4 a component of the multiprotein complex splicing factor 3b (SF3B), an integral part of the U2 small nuclear ribonucleoprotein (snRNP) and the U11/U12 di-snRNP. SF3B is essential for the accurate excision of introns from pre-messenger RNA, and is involved in the recognition of the pre-mRNA's branch site within the major and minor spliceosomes. SF3B4 functions to tether U2 snRNP with pre-mRNA at the branch site during spliceosome assembly. It is an evolutionarily highly conserved protein with orthologs across diverse species. SF3B4 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It binds directly to pre-mRNA and also interacts directly and highly specifically with another SF3B subunit called SAP 145.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDK-DGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12334    1 VYVGNLDEKVTEELLWELFIQAGPVVNVHMPKDRvTQQHQGYGFVEFLSEEDADYAIKIMNMIKLYGKPIRV 72

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQ 83
Cdd:cd00590    1 LFVGNLPPDTTEEDLRELFSKFGEVVSVRIVRDRDGKSKGFAFVEFESPEDAEKALEALNGTELGGRPLKVS 72

RNA recognition motif (RRM) found in cleavage stimulation factor subunit 2 (CSTF2), yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins; This subfamily 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. The family also includes yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins. RNA15 is a core subunit of cleavage factor IA (CFIA), an essential transcriptional 3'-end processing factor from Saccharomyces cerevisiae. RNA recognition by CFIA is mediated by an N-terminal RRM, which is contained in the RNA15 subunit of the complex. The RRM of RNA15 has a strong preference for GU-rich RNAs, mediated by a binding pocket that is entirely conserved in both yeast and vertebrate RNA15 orthologs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12398    1 RSVFVGNIPYDATEEQLKEIFSEVGPVVSFRLVTDREtGKPKGYGFCEFRDAETALSAVRNLNGYELNGRPLRVDF 76

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:COG0724    3 KIYVGNLPYSVTEEDLRELFSEYGEVTSVKLITDREtGRSRGFGFVEMPDDEEAQAAIEALNGAELMGRTLKV 75

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 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNlLNGIKLYGRPIKIQ 83
Cdd:cd12395    1 SVFVGNLPFDIEEEELRKHFEDCGDVEAVRIVRDREtGIGKGFGYVLFKDKDSVDLALK-LNGSKLRGRKLRVK 73

RNA recognition motif (RRM) found in eukaryotic RNA-binding protein 25 and similar proteins; This subfamily corresponds to the RRM of RBM25, also termed Arg/Glu/Asp-rich protein of 120 kDa (RED120), or protein S164, or RNA-binding region-containing protein 7, an evolutionary-conserved splicing coactivator SRm160 (SR-related nuclear matrix protein of 160 kDa, )-interacting protein. RBM25 belongs to a family of RNA-binding proteins containing a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), at the N-terminus, a RE/RD-rich (ER) central region, and a C-terminal proline-tryptophan-isoleucine (PWI) motif. It localizes to the nuclear speckles and associates with multiple splicing components, including splicing cofactors SRm160/300, U snRNAs, assembled splicing complexes, and spliced mRNAs. It may play an important role in pre-mRNA processing by coupling splicing with mRNA 3'-end formation. Additional research indicates that RBM25 is one of the RNA-binding regulators that direct the alternative splicing of apoptotic factors. It can activate proapoptotic Bcl-xS 5'ss by binding to the exonic splicing enhancer, CGGGCA, and stabilize the pre-mRNA-U1 snRNP through interaction with hLuc7A, a U1 snRNP-associated factor.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12446    1 TTVFVGNIPDDVSDDFIRQLLEKCGKVLSWKRVQDPSGKLKAFGFCEFEDPEGALRALRLLNGLELGGKKLLV 73

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein M (hnRNP M) and similar proteins; This subfamily corresponds to the RRM2 of heterogeneous nuclear ribonucleoprotein M (hnRNP M), myelin expression factor 2 (MEF-2 or MyEF-2 or MST156) and similar proteins. hnRNP M is pre-mRNA binding protein that may play an important role in the pre-mRNA processing. It also preferentially binds to poly(G) and poly(U) RNA homopolymers. hnRNP M is able to interact with early spliceosomes, further influencing splicing patterns of specific pre-mRNAs. It functions as the receptor of carcinoembryonic antigen (CEA) that contains the penta-peptide sequence PELPK signaling motif. In addition, hnRNP M and another splicing factor Nova-1 work together as dopamine D2 receptor (D2R) pre-mRNA-binding proteins. They regulate alternative splicing of D2R pre-mRNA in an antagonistic manner. hnRNP M contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an unusual hexapeptide-repeat region rich in methionine and arginine residues (MR repeat motif). MEF-2 is a sequence-specific single-stranded DNA (ssDNA) binding protein that binds specifically to ssDNA derived from the proximal (MB1) element of the myelin basic protein (MBP) promoter and represses transcription of the MBP gene. MEF-2 shows high sequence homology with hnRNP M. It also contains three RRMs, which may be responsible for its ssDNA binding activity.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQ 83
Cdd:cd12386    1 IFVANLDYKVGWKKLKEVFKLAGKVVRADIREDKDGKSRGMGVVQFEHPIEAVQAISMFNGQMLFDRPMRVK 72

RNA recognition motif 1 (RRM1) found in yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1 and similar proteins; This subgroup corresponds to the RRM1 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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12614    1 LYVGNLDPRVTEDLLQEIFAVTGPVENCKIIPDKNSKGVNYGFVEYYDRRSAEIAIQTLNGRQIFGQEIKV 71

RNA recognition motif (RRM) found in Helicobacter pylori HP0827 protein and similar proteins; This subfamily corresponds to the RRM of H. pylori HP0827, a putative ssDNA-binding protein 12rnp2 precursor, containing one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The ssDNA binding may be important in activation of HP0827.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12399    1 LYVGNLPYSASEEQLKSLFGQFGAVFDVKLPMDREtKRPRGFGFVELQEEESAEKAIAKLDGTDFMGRTIRVNE 74

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12284    1 LYVGSLHFNITEDMLRGIFEPFGKIEFVQLQKDPEtGRSKGYGFIQFRDAEDAKKALEQLNGFELAGRPMKV 72

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein R (hnRNP R) and similar proteins; This subfamily corresponds to the RRM3 in hnRNP R, hnRNP Q, and APOBEC-1 complementation factor (ACF). hnRNP R is a ubiquitously expressed nuclear RNA-binding protein that specifically bind mRNAs with a preference for poly(U) stretches and has been implicated in mRNA processing and mRNA transport, and also acts as a regulator to modify binding to ribosomes and RNA translation. hnRNP Q is also a ubiquitously expressed nuclear RNA-binding protein. It has been identified as a component of the spliceosome complex, as well as a component of the apobec-1 editosome, and has been implicated in the regulation of specific mRNA transport. ACF is an RNA-binding subunit of a core complex that interacts with apoB mRNA to facilitate C to U RNA editing. It may also act as an apoB mRNA recognition factor and chaperone and play a key role in cell growth and differentiation. This family also includes two functionally unknown RNA-binding proteins, RBM46 and RBM47. All members contain three conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDkdgkpkqFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12251    2 KVLYVRNLMLSTTEEKLRELFSEYGKVERVKKIKD-------YAFVHFEERDDAVKAMEEMNGKELEGSEIEVSL 69

RNA recognition motif 2 (RRM2) found in vertebrate nucleolin; This subfamily corresponds to the RRM2 of ubiquitously expressed protein nucleolin, also termed protein C23, a multifunctional major nucleolar phosphoprotein that has been implicated in various metabolic processes, such as ribosome biogenesis, cytokinesis, nucleogenesis, cell proliferation and growth, cytoplasmic-nucleolar transport of ribosomal components, transcriptional repression, replication, signal transduction, inducing chromatin decondensation, etc. Nucleolin exhibits intrinsic self-cleaving, DNA helicase, RNA helicase and DNA-dependent ATPase activities. It can be phosphorylated by many protein kinases, such as the major mitotic kinase Cdc2, casein kinase 2 (CK2), and protein kinase C-zeta. Nucleolin shares similar domain architecture with gar2 from Schizosaccharomyces pombe and NSR1 from Saccharomyces cerevisiae. The highly phosphorylated N-terminal domain of nucleolin is made up of highly acidic regions separated from each other by basic sequences, and contains multiple phosphorylation sites. The central domain of nucleolin contains four closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), which suggests that nucleolin is potentially able to interact with multiple RNA targets. The C-terminal RGG (or GAR) domain of nucleolin is rich in glycine, arginine and phenylalanine residues, and contains high levels of NG,NG-dimethylarginines.RRM2, together with RRM1, binds specifically to RNA stem-loops containing the sequence (U/G)CCCG(A/G) in the loop.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAgpvIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12404    4 RTLFVKNLPYSTTQDELKEVFEDA---VDIRIPMGRDGRSKGIAYIEFKSEAEAEKALEEKQGTEVDGRSIVVDY 75

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGK-PKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQFRSG 87
Cdd:cd12240    1 LYVGNLSFYTTEEQIYELFSKCGDIKRIIMGLDKFKKtPCGFCFVEYYSREDAENAVKYLNGTKLDDRIIRVDWDAG 77

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKpKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12352    1 LYVGNLDRQVTEDLILQLFSQIGPCKSCKMITEHGGN-DPYCFVEFYEHNHAAAALQAMNGRKILGKEVKV 70

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        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKD-KDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQFRSG 87
Cdd:cd12236    2 KTLFVARLSYDTTESKLRREFEKYGPIKRVRLVRDkKTGKSRGYAFIEFEHERDMKAAYKHADGKKIDGRRVLVDVERG 80

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNF-KHEvSVPYAMNLLNGIKLYGRPI 80
Cdd:cd12380    4 VYVKNFGEDVDDDELKELFEKYGKITSAKVMKDDSGKSKGFGFVNFeNHE-AAQKAVEELNGKELNGKKL 72

RNA recognition motif 2 (RRM2) found in vertebrate myelin expression factor 2 (MEF-2); This subgroup corresponds to the RRM2 of MEF-2, also termed MyEF-2 or MST156, a sequence-specific single-stranded DNA (ssDNA) binding protein that binds specifically to ssDNA derived from the proximal (MB1) element of the myelin basic protein (MBP) promoter and represses transcription of the MBP gene. MEF-2 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), which may be responsible for its ssDNA binding activity.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQ 83
Cdd:cd12660    2 TIFVANLDFKVGWKKLKEVFSMAGTVKRADIKEDKDGKSRGMGTVTFEQAIEAVQAISMFNGQFLFDRPMHVK 74

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 554506545    9 DRTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNlLNGIKLYGRPIKIQF--- 84
Cdd:TIGR01622 114 RRTVFVQQLAARARERDLYEFFSKVGKVRDVQIIKDRNsRRSKGVGYVEFYDVDSVQAALA-LTGQKLLGIPVIVQLsea 192

                          90       100
                  ....*....|....*....|....*....
gi 554506545   85 -----RSGSSHAPQDVSLSYPQH--HVGN 106
Cdd:TIGR01622 193 eknraARAATETSGHHPNSIPFHrlYVGN 221

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 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNlLNGIKLYGRPIKI 82
Cdd:cd12272    1 TVYIGNLAWDIDEDDLRELFAECCEITNVRLHTDKEtGEFKGYGHVEFADEESLDAALK-LAGTKLCGRPIRV 72

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12411   12 IYIGGLPYELTEGDILCVFSQYGEIVDINLVRDKKtGKSKGFAFLAYEDQRSTILAVDNLNGIKLLGRTIRV 83

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506545   8 ADRTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPkqFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12350    1 ATRTLFIGNLEKTTTYGDLRNIFERFGEIIDIDIKKQNGNPQ--YAFLQYCDIASVVKAIKKMDGEYLGNNRLKL 73

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12680    2 KLLVSNLDFGVSDADIKELFAEFGTLKKAAVHYDRSGRSLGTAEVVFERRADALKAMKQYNGVPLDGRPMKIQL 75

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 554506545  23 EELLFELFHQAGPVIKVKIPKDKDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12675   15 PVHLKKLFGRYGKVVEATIPRKKGGKLSGFAFVTMKGRKNAEEALESVNGLEIDGRPVAVDW 76

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 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPI 80
Cdd:cd21608    1 KLYVGNLSWDTTEDDLRDLFSEFGEVESAKVITDREtGRSRGFGFVTFSTAEAAEAAIDALNGKELDGRSI 71

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 554506545  11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKD-KDGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQFR 85
Cdd:cd12377    1 CIFVYNLAPDADESLLWQLFGPFGAVQNVKIIRDfTTNKCKGYGFVTMTNYDEAAVAIASLNGYRLGGRVLQVSFK 76

RNA recognition motif 3 (RRM3) found in vertebrate heterogeneous nuclear ribonucleoprotein Q (hnRNP Q); This subgroup corresponds to the RRM3 of hnRNP Q, also termed glycine- and tyrosine-rich RNA-binding protein (GRY-RBP), or NS1-associated protein 1 (NASP1), or synaptotagmin-binding, cytoplasmic RNA-interacting protein (SYNCRIP). It is a ubiquitously expressed nuclear RNA-binding protein identified as a component of the spliceosome complex, as well as a component of the apobec-1 editosome. As an alternatively spliced version of NSAP, it acts as an interaction partner of a multifunctional protein required for viral replication, and is implicated in the regulation of specific mRNA transport. hnRNP Q has also been identified as SYNCRIP that is a dual functional protein participating in both viral RNA replication and translation. As a synaptotagmin-binding protein, hnRNP Q plays a putative role in organelle-based mRNA transport along the cytoskeleton. Moreover, hnRNP Q has been found in protein complexes involved in translationally coupled mRNA turnover and mRNA splicing. It functions as a wild-type survival motor neuron (SMN)-binding protein that may participate in pre-mRNA splicing and modulate mRNA transport along microtubuli. hnRNP Q contains an acidic auxiliary N-terminal region, followed by two well defined and one degenerated RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal RGG motif; hnRNP Q binds RNA through its RRM domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKipkdkdgKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKIQF 84
Cdd:cd12495    2 KVLFVRNLANTVTEEILEKAFSQFGKLERVK-------KLKDYAFIHFDERDGAVKAMDEMNGKDLEGENIEIVF 69

RNA recognition motif 3 (RRM3) found in vertebrate heterogeneous nuclear ribonucleoprotein R (hnRNP R); This subgroup corresponds to the RRM3 of hnRNP R. a ubiquitously expressed nuclear RNA-binding protein that specifically bind mRNAs with a preference for poly(U) stretches. Upon binding of RNA, hnRNP R forms oligomers, most probably dimers. hnRNP R has been implicated in mRNA processing and mRNA transport, and also acts as a regulator to modify binding to ribosomes and RNA translation. hnRNP R is predominantly located in axons of motor neurons and to a much lower degree in sensory axons. In axons of motor neurons, it also functions as a cytosolic protein and interacts with wild type of survival motor neuron (SMN) proteins directly, further providing a molecular link between SMN and the spliceosome. Moreover, hnRNP R plays an important role in neural differentiation and development, as well as in retinal development and light-elicited cellular activities. hnRNP R contains an acidic auxiliary N-terminal region, followed by two well-defined and one degenerated RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal RGG motif; hnRNP R binds RNA through its RRM domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKipkdkdgKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12494    2 KVLFVRNLATTVTEEILEKTFSQFGKLERVK-------KLKDYAFVHFEDRDAAVKAMDEMNGKEVEGEEIEI 67

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 554506545    5 AAEADRTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:TIGR01622 210 NSIPFHRLYVGNLHFNITEQDLRQIFEPFGEIEFVQLQKDPEtGRSKGYGFIQFRDAEQAKEALEKMNGFELAGRPIKV 288

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 554506545  10 RTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFK 58
Cdd:cd12415    1 KTVFIRNLSFDTTEEDLKEFFSKFGEVKYARIVLDKDtGHSKGTAFVQFK 50

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12449    3 LFVGGLSFDTNEQSLEEVFSKYGQISEVVVVKDREtQRSRGFGFVTFENPDDAKDAMMAMNGKSLDGRQIRV 74

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 554506545  12 LFVGNLETKVTEELLFELFHQAGPVIKVKIPKDKD-GKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12382    4 LFIGGLNTETNEKALEAVFGKYGRIVEVLLMKDREtNKSRGFAFVTFESPADAKDAARDMNGKELDGKAIKV 75

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

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 554506545   11 TLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDK-DGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:TIGR01628   2 SLYVGDLDPDVTEAKLYDLFKPFGPVLSVRVCRDSvTRRSLGYGYVNFQNPADAERALETMNFKRLGGKPIRI 74

RNA recognition motif (RRM) found in RNA-binding protein 42 (RBM42) and similar proteins; This subfamily corresponds to the RRM of RBM42 which has been identified as a heterogeneous nuclear ribonucleoprotein K (hnRNP K)-binding protein. It also directly binds the 3' untranslated region of p21 mRNA that is one of the target mRNAs for hnRNP K. Both, hnRNP K and RBM42, are components of stress granules (SGs). Under nonstress conditions, RBM42 predominantly localizes within the nucleus and co-localizes with hnRNP K. Under stress conditions, hnRNP K and RBM42 form cytoplasmic foci where the SG marker TIAR localizes, and may play a role in the maintenance of cellular ATP level by protecting their target mRNAs. RBM42 contains an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

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gi 554506545   7 EADRTLFVGNLETKVTEELLFELFHQAGPVIKVKIPKDK-DGKPKQFAFVNFKHEVSVPYAMNLLNGIKLYGRPIKI 82
Cdd:cd12383    4 PNDFRIFCGDLGNEVTDEVLARAFSKYPSFQKAKVIRDKrTGKSKGYGFVSFKDPNDYLKALREMNGKYVGNRPIKL 80