Nuclear transport factor 2 (NTF2) domain plays an important role in the trafficking of macromolecules, ions and small molecules between the cytoplasm and nucleus. This bi-directional transport of macromolecules across the nuclear envelope requires many soluble factors that includes GDP-binding protein Ran (RanGDP). RanGDP is required for both import and export of proteins and poly(A) RNA. RanGDP also has been implicated in cell cycle control, specifically in mitotic spindle assembly. In interphase cells, RanGDP is predominately nuclear and thought to be GTP bound, but it is also present in the cytoplasm, probably in the GDP-bound state. NTF2 mediates the nuclear import of RanGDP. NTF2 binds to both RanGDP and FxFG repeat-containing nucleoporins.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455  12 AEVVGRAFVEQYYHILHQSPGLVHRFYQDSSFLTRPDVTGAVTtvttMQAINDKILSLKYEDYTAEIETADAQESHERGV 91
Cdd:cd00780   2 AEDVAKAFVQQYYSIFDNNREGLHRLYGDTSMLSREGMKQVTG----RDAIVEKLSSLPFQKTKHKITTVDSQPTPSGGV 77

                        90       100       110       120
                ....*....|....*....|....*....|....*....|
gi 30697455  92 IVLVTGRLTGNDNVRKKFSQSFFLAPQDKGYFVLNDVFRF 131
Cdd:cd00780  78 IVMVTGSLKLDEQPPRKFSQTFVLAPQNGGYFVLNDIFRF 117

Nuclear transport factor 2 (NTF2) domain plays an important role in the trafficking of macromolecules, ions and small molecules between the cytoplasm and nucleus. This bi-directional transport of macromolecules across the nuclear envelope requires many soluble factors that includes GDP-binding protein Ran (RanGDP). RanGDP is required for both import and export of proteins and poly(A) RNA. RanGDP also has been implicated in cell cycle control, specifically in mitotic spindle assembly. In interphase cells, RanGDP is predominately nuclear and thought to be GTP bound, but it is also present in the cytoplasm, probably in the GDP-bound state. NTF2 mediates the nuclear import of RanGDP. NTF2 binds to both RanGDP and FxFG repeat-containing nucleoporins.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455  12 AEVVGRAFVEQYYHILHQSPGLVHRFYQDSSFLTRPDVTGAVTtvttMQAINDKILSLKYEDYTAEIETADAQESHERGV 91
Cdd:cd00780   2 AEDVAKAFVQQYYSIFDNNREGLHRLYGDTSMLSREGMKQVTG----RDAIVEKLSSLPFQKTKHKITTVDSQPTPSGGV 77

                        90       100       110       120
                ....*....|....*....|....*....|....*....|
gi 30697455  92 IVLVTGRLTGNDNVRKKFSQSFFLAPQDKGYFVLNDVFRF 131
Cdd:cd00780  78 IVMVTGSLKLDEQPPRKFSQTFVLAPQNGGYFVLNDIFRF 117

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 30697455    294 SIYVRNLPFDSTPTQLEEVFKNFGAIKHegIQVRSNKQQGFC--FGFVEFETSSGKQSALEA-SPVTIGDRQAVV 365
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVES--VRLVRDKETGKSkgFAFVEFESEEDAEKALEAlNGKELDGRPLKV 73

RNA recognition motif (RRM) superfamily; RRM, also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), is a highly abundant domain in eukaryotes found in proteins involved in post-transcriptional gene expression processes including mRNA and rRNA processing, RNA export, and RNA stability. This domain is 90 amino acids in length and consists of a four-stranded beta-sheet packed against two alpha-helices. RRM usually interacts with ssRNA, but is also known to interact with ssDNA as well as proteins. RRM binds a variable number of nucleotides, ranging from two to eight. The active site includes three aromatic side-chains located within the conserved RNP1 and RNP2 motifs of the domain. The RRM domain is found in a variety heterogeneous nuclear ribonucleoproteins (hnRNPs), proteins implicated in regulation of alternative splicing, and protein components of small nuclear ribonucleoproteins (snRNPs).

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHegIQVRSNKQQGF-CFGFVEFETSSGKQSALEA 353
Cdd:cd00590   1 LFVGNLPPDTTEEDLRELFSKFGEVVS--VRIVRDRDGKSkGFAFVEFESPEDAEKALEA 58

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 30697455   295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQvRSNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:TIGR01628 181 LYVKNLDPSVNEDKLRELFAKFGEITSAAVM-KDGSGRSRGFAFVNFEKHEDAAKAVEE 238

Nuclear transport factor 2 (NTF2) domain plays an important role in the trafficking of macromolecules, ions and small molecules between the cytoplasm and nucleus. This bi-directional transport of macromolecules across the nuclear envelope requires many soluble factors that includes GDP-binding protein Ran (RanGDP). RanGDP is required for both import and export of proteins and poly(A) RNA. RanGDP also has been implicated in cell cycle control, specifically in mitotic spindle assembly. In interphase cells, RanGDP is predominately nuclear and thought to be GTP bound, but it is also present in the cytoplasm, probably in the GDP-bound state. NTF2 mediates the nuclear import of RanGDP. NTF2 binds to both RanGDP and FxFG repeat-containing nucleoporins.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455  12 AEVVGRAFVEQYYHILHQSPGLVHRFYQDSSFLTRPDVTGAVTtvttMQAINDKILSLKYEDYTAEIETADAQESHERGV 91
Cdd:cd00780   2 AEDVAKAFVQQYYSIFDNNREGLHRLYGDTSMLSREGMKQVTG----RDAIVEKLSSLPFQKTKHKITTVDSQPTPSGGV 77

                        90       100       110       120
                ....*....|....*....|....*....|....*....|
gi 30697455  92 IVLVTGRLTGNDNVRKKFSQSFFLAPQDKGYFVLNDVFRF 131
Cdd:cd00780  78 IVMVTGSLKLDEQPPRKFSQTFVLAPQNGGYFVLNDIFRF 117

Nuclear transport factor 2 (NTF2-like) superfamily. This family includes members of the NTF2 family, Delta-5-3-ketosteroid isomerases, Scytalone Dehydratases, and the beta subunit of Ring hydroxylating dioxygenases. This family is a classic example of divergent evolution wherein the proteins have many common structural details but diverge greatly in their function. For example, nuclear transport factor 2 (NTF2) mediates the nuclear import of RanGDP and binds to both RanGDP and FxFG repeat-containing nucleoporins while Ketosteroid isomerases catalyze the isomerization of delta-5-3-ketosteroid to delta-4-3-ketosteroid, by intramolecular transfer of the C4-beta proton to the C6-beta position. While the function of the beta sub-unit of the Ring hydroxylating dioxygenases is not known, Scytalone Dehydratases catalyzes two reactions in the biosynthetic pathway that produces fungal melanin. Members of the NTF2-like superfamily are widely distributed among bacteria, archaea and eukaryotes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455  16 GRAFVEQYYHILH-QSPGLVHRFYQDSSFLTRPDVTGAVTTVTTMQAINDKILSLKYEDYTAE--IETADAQESHER-GV 91
Cdd:cd00531   1 AEQFLYRYARLLDaGDREWLALLYADDAYFEPPGGDGLIYPDDGREAIEDRVRRLPFGPSRTRhlVSNVDVQPGDDGeGV 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|...
gi 30697455  92 IVLVTGRLT---GNDNVRKKFSQSFFLAPQDKGYFVLNDVFRF 131
Cdd:cd00531  81 VVSVFGVLRtrgDGEQDVFAGGQTFVLRPQGGGGKIANRRFRL 123

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455   295 IYVRNLPFDSTPTQLEEVFKNFGAIKHegIQV-RSNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKS--IRLvRDETGRSKGFAFVEFEDEEDAEKAIEA 58

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 30697455 294 SIYVRNLPFDSTPTQLEEVFKNFGAIKHegIQVRSNKQQGFC--FGFVEFETSSGKQSALEA-SPVTIGDRQAVVEEKK 369
Cdd:COG0724   3 KIYVGNLPYSVTEEDLRELFSEYGEVTS--VKLITDRETGRSrgFGFVEMPDDEEAQAAIEAlNGAELMGRTLKVNEAR 79

RNA recognition motif 3 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM3 of Prp24, also termed U4/U6 snRNA-associated-splicing factor PRP24 (U4/U6 snRNP), an RNA-binding protein with four well conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It facilitates U6 RNA base-pairing with U4 RNA during spliceosome assembly. Prp24 specifically binds free U6 RNA primarily with RRMs 1 and 2 and facilitates pairing of U6 RNA bases with U4 RNA bases. Additionally, it may also be involved in dissociation of the U4/U6 complex during spliceosome activation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGF---CFGFVEFETSSGKQSALEASPVTIGDR 361
Cdd:cd12298   3 IRVRNLDFELDEEALRGIFEKFGEIESINIPKKQKNRKGRhnnGFAFVTFEDADSAESALQLNGTLLDNR 72

RNA recognition motif 1 (RRM1) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM1 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30697455 294 SIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIqVRsNKQQGFC--FGFVEFETSSGKQSALE 352
Cdd:cd12413   1 TLFVRNLPYDTTDEQLEELFSDVGPVKRCFV-VK-DKGKDKCrgFGYVTFALAEDAQRALE 59

RNA recognition motif 6 (RRM6) found in RNA-binding protein 19 (RBM19) and similar proteins; This subgroup corresponds to the RRM6 of RBM19, also termed RNA-binding domain-1 (RBD-1), which is a nucleolar protein conserved in eukaryotes. It is involved in ribosome biogenesis by processing rRNA. In addition, it is essential for preimplantation development. RBM19 has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKhegiQVR-----SNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:cd12571   3 ILVRNIPFQATVKEVRELFSTFGELK----TVRlpkkmGGTGQHRGFGFVDFITKQDAKRAFDA 62

RNA recognition motif in type II polyadenylate-binding proteins; This subfamily corresponds to the RRM of type II polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 2 (PABP-2 or PABPN1), embryonic polyadenylate-binding protein 2 (ePABP-2 or PABPN1L) and similar proteins. PABPs are highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. ePABP-2 is predominantly located in the cytoplasm and PABP-2 is located in the nucleus. In contrast to the type I PABPs containing four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), the type II PABPs contains a single highly-conserved RRM. This subfamily also includes Saccharomyces cerevisiae RBP29 (SGN1, YIR001C) gene encoding cytoplasmic mRNA-binding protein Rbp29 that binds preferentially to poly(A). Although not essential for cell viability, Rbp29 plays a role in modulating the expression of cytoplasmic mRNA. Like other type II PABPs, Rbp29 contains one RRM only.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 30697455 294 SIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEASPVTIGDRQAVV 365
Cdd:cd12306   1 SIYVGNVDYGTTPEELQAHFKSCGTINRVTILCDKFTGQPKGFAYIEFVDKSSVENALLLNESEFRGRQIKV 72

RNA recognition motif (RRM) found in ras GTPase-activating protein-binding protein 1 (G3BP1) and similar proteins; This subgroup corresponds to the RRM of G3BP1, also termed ATP-dependent DNA helicase VIII (DH VIII), or GAP SH3 domain-binding protein 1, which has been identified as a phosphorylation-dependent endoribonuclease that interacts with the SH3 domain of RasGAP, a multi-functional protein controlling Ras activity. The acidic RasGAP binding domain of G3BP1 harbors an arsenite-regulated phosphorylation site and dominantly inhibits stress granule (SG) formation. G3BP1 also contains an N-terminal nuclear transfer factor 2 (NTF2)-like domain, an RNA recognition motif (RRM domain), and an Arg-Gly-rich region (RGG-rich region, or arginine methylation motif). The RRM domain and RGG-rich region are canonically associated with RNA binding. G3BP1 co-immunoprecipitates with mRNAs. It binds to and cleaves the 3'-untranslated region (3'-UTR) of the c-myc mRNA in a phosphorylation-dependent manner. Thus, G3BP1 may play a role in coupling extra-cellular stimuli to mRNA stability. It has been shown that G3BP1 is a novel Dishevelled-associated protein that is methylated upon Wnt3a stimulation and that arginine methylation of G3BP1 regulates both Ctnnb1 mRNA and canonical Wnt/beta-catenin signaling. Furthermore, G3BP1 can be associated with the 3'-UTR of beta-F1 mRNA in cytoplasmic RNA-granules, demonstrating that G3BP1 may specifically repress the translation of the transcript.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455 291 DGHSIYVRNLPFDSTPTQLEEVFKNFGAIkhegIQVRSN-KQQGFCFGFVEFETSSGKQSALEASPVTI-GDRQAVVEEK 368
Cdd:cd12463   2 DSHQLFVGNLPHDVDKSELKEFFQGYGNV----VELRINsGGKLPNFGFVVFDDPEPVQKILSNRPIKFrGEVRLNVEEK 77

                ..
gi 30697455 369 KT 370
Cdd:cd12463  78 KT 79

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 30697455 294 SIYVRNLPF----DSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEASPVTIGDRQAVVEE 367
Cdd:cd12451   1 TIFVKGFDAslgeDTIRDELREHFGECGEVTNVRIPTDRETGELKGFAYIEFSTKEAKEKALELNGSDIAGGNLVVDE 78

RNA recognition motif 5 (RRM5) found in RNA-binding protein 19 (RBM19 or RBD-1) and similar proteins; This subfamily corresponds to the RRM5 of RBM19 and RRM4 of MRD1. RBM19, also termed RNA-binding domain-1 (RBD-1), is a nucleolar protein conserved in eukaryotes involved in ribosome biogenesis by processing rRNA and is essential for preimplantation development. It has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVR---SNKQQGFCFGFVEFETSSGKQSALE 352
Cdd:cd12318   1 TTLFVKNLNFKTTEEALKKHFEKCGPIRSVTIAKKkdpKGPLLSMGYGFVEFKSPEAAQKALK 63

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein M (hnRNP M) and similar proteins; This subfamily corresponds to the RRM3 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. hnRNP M functions as the receptor of carcinoembryonic antigen (CEA) that contains the penta-peptide sequence PELPK signaling motif. In addition, hnRNP M and another splicing factor Nova-1 work together as dopamine D2 receptor (D2R) pre-mRNA-binding proteins. They regulate alternative splicing of D2R pre-mRNA in an antagonistic manner. hnRNP M contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an unusual hexapeptide-repeat region rich in methionine and arginine residues (MR repeat motif). MEF-2 is a sequence-specific single-stranded DNA (ssDNA) binding protein that binds specifically to ssDNA derived from the proximal (MB1) element of the myelin basic protein (MBP) promoter and represses transcription of the MBP gene. MEF-2 shows high sequence homology with hnRNP M. It also contains three RRMs, which may be responsible for its ssDNA binding activity.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGfcFGFVEFETSSGKQSA 350
Cdd:cd12387   1 IFVRNLPFDYTWQKLKDKFKDCGHVTFASIKMENGKSKG--CGTVRFDSPEDAENA 54

RNA recognition motif 3 (RRM3) found in RNA-binding protein 19 (RBM19) and RNA recognition motif 2 found in multiple RNA-binding domain-containing protein 1 (MRD1); This subfamily corresponds to the RRM3 of RBM19 and RRM2 of MRD1. RBM19, also termed RNA-binding domain-1 (RBD-1), is a nucleolar protein conserved in eukaryotes involved in ribosome biogenesis by processing rRNA and is essential for preimplantation development. It has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). MRD1 is encoded by a novel yeast gene MRD1 (multiple RNA-binding domain). It is well conserved in yeast and its homologs exist in all eukaryotes. MRD1 is present in the nucleolus and the nucleoplasm. It interacts with the 35 S precursor rRNA (pre-rRNA) and U3 small nucleolar RNAs (snoRNAs). It is essential for the initial processing at the A0-A2 cleavage sites in the 35 S pre-rRNA. MRD1 contains 5 conserved RRMs, which may play an important structural role in organizing specific rRNA processing events.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIK--HEGIQVRSNKQQGfcFGFVEFETSSGKQSALEA 353
Cdd:cd12316   2 LFVRNLPFTATEDELRELFEAFGKISevHIPLDKQTKRSKG--FAFVLFVIPEDAVKAYQE 60

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30697455 297 VRNLPFDSTPTQLEEVFKNFGAIkhEGIQV---RSNKQQGfcFGFVEFETSSGKQSALEASPVT-IGDRQAVV 365
Cdd:cd12414   4 VRNLPFKCTEDDLKKLFSKFGKV--LEVTIpkkPDGKLRG--FAFVQFTNVADAAKAIKGMNGKkIKGRPVAV 72

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEASPVTIGDRQavVEEKK 369
Cdd:cd12330   2 IFVGGLAPDVTEEEFKEYFEQFGTVVDAVVMLDHDTGRSRGFGFVTFDSESAVEKVLSKGFHELGGKK--VEVKR 74

RNA recognition motif 1 (RRM1) found in (U)-binding-splicing factor PUF60 and similar proteins; This subfamily corresponds to the RRM1 of PUF60, also termed FUSE-binding protein-interacting repressor (FBP-interacting repressor or FIR), or Ro-binding protein 1 (RoBP1), or Siah-binding protein 1 (Siah-BP1). PUF60 is an essential splicing factor that functions as a poly-U RNA-binding protein required to reconstitute splicing in depleted nuclear extracts. Its function is enhanced through interaction with U2 auxiliary factor U2AF65. PUF60 also controls human c-myc gene expression by binding and inhibiting the transcription factor far upstream sequence element (FUSE)-binding-protein (FBP), an activator of c-myc promoters. PUF60 contains two central RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal U2AF (U2 auxiliary factor) homology motifs (UHM) that harbors another RRM and binds to tryptophan-containing linear peptide motifs (UHM ligand motifs, ULMs) in several nuclear proteins. Research indicates that PUF60 binds FUSE as a dimer, and only the first two RRM domains participate in the single-stranded DNA recognition.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGI---QVrSNKQQGFCfgFVEFETSSGKQSALEA-SPVTIGDR 361
Cdd:cd12370   3 VYVGSIYFELGEDTIRQAFAPFGPIKSIDMswdPV-TMKHKGFA--FVEYEVPEAAQLALEQmNGVMLGGR 70

RNA recognition motif 2 (RRM2) found in yeast multiple RNA-binding domain-containing protein 1 (MRD1) and similar proteins; This subgroup corresponds to the RRM2 of MRD1 which is encoded by a novel yeast gene MRD1 (multiple RNA-binding domain). It is well-conserved in yeast and its homologs exist in all eukaryotes. MRD1 is present in the nucleolus and the nucleoplasm. It interacts with the 35 S precursor rRNA (pre-rRNA) and U3 small nucleolar RNAs (snoRNAs). It is essential for the initial processing at the A0-A2 cleavage sites in the 35 S pre-rRNA. MRD1 contains 5 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), which may play an important structural role in organizing specific rRNA processing events.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIK--HEGIQVRSNKQQGFCF-GFVEFETSSGKQSALEASP 355
Cdd:cd12566   5 LFLRNLPYSTKEDDLQKLFSKFGEVSevHVPIDKKTKKSKGFAYvLFLDPEDAVQAYNELDGKV 68

RNA recognition motif 2 (RRM2) found in (U)-binding-splicing factor PUF60 and similar proteins; This subfamily corresponds to the RRM2 of PUF60, also termed FUSE-binding protein-interacting repressor (FBP-interacting repressor or FIR), or Ro-binding protein 1 (RoBP1), or Siah-binding protein 1 (Siah-BP1). PUF60 is an essential splicing factor that functions as a poly-U RNA-binding protein required to reconstitute splicing in depleted nuclear extracts. Its function is enhanced through interaction with U2 auxiliary factor U2AF65. PUF60 also controls human c-myc gene expression by binding and inhibiting the transcription factor far upstream sequence element (FUSE)-binding-protein (FBP), an activator of c-myc promoters. PUF60 contains two central RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal U2AF (U2 auxiliary factor) homology motifs (UHM) that harbors another RRM and binds to tryptophan-containing linear peptide motifs (UHM ligand motifs, ULMs) in several nuclear proteins. Research indicates that PUF60 binds FUSE as a dimer, and only the first two RRM domains participate in the single-stranded DNA recognition.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKHEGI--QVRSNKQQGfcFGFVEFETSsgkQSALEA 353
Cdd:cd12371   1 NRIYVASVHPDLSEDDIKSVFEAFGKIKSCSLapDPETGKHKG--YGFIEYENP---QSAQDA 58

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEASPVTIGDRQAVVE 366
Cdd:cd12514   2 IRITNLPYDATPVDIQRFFEDHGVRPEDVHLLRNKKGRGNGEALVTFKSEGDAREVLKLNGKKLGKREAVVE 73

RNA recognition motif 1 (RRM1) found in Saccharomyces cerevisiae protein HRB1, G-strand-binding protein 2 (GBP2) and similar proteins; The family includes Saccharomyces cerevisiae protein HRB1 (also called protein TOM34) and GBP2, both of which are SR-like mRNA-binding proteins which shuttle from the nucleus to the cytoplasm when bound to the mature mRNA molecules. They act as quality control factors for spliced mRNAs. GBP2, also called RAP1 localization factor 6, is a single-strand telomeric DNA-binding protein that binds single-stranded telomeric sequences of the type (TG[1-3])n in vitro. It also binds to RNA. GBP2 influences the localization of RAP1 in the nuclei and plays a role in modulating telomere length. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the first RRM motif.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 30697455 294 SIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGfcFGFVEFETSSGKQSALE 352
Cdd:cd21605   3 SIFVGNLPFDCTWEDLKDHFSQVGEVIRADIVTSRGRHRG--MGTVEFTNKEDVDRAIS 59

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
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKHegiqVR------SNKQQGfcFGFVEFETSSGKQSA 350
Cdd:cd12398   1 RSVFVGNIPYDATEEQLKEIFSEVGPVVS----FRlvtdreTGKPKG--YGFCEFRDAETALSA 58

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
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIqVRSNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:cd12380   4 VYVKNFGEDVDDDELKELFEKYGKITSAKV-MKDDSGKSKGFGFVNFENHEAAQKAVEE 61

RNA recognition motif 3 (RRM3) found in vertebrate heterogeneous nuclear ribonucleoprotein M (hnRNP M); This subgroup corresponds to the RRM3 of hnRNP M, a pre-mRNA binding protein that may play an important role in the pre-mRNA processing. It also preferentially binds to poly(G) and poly(U) RNA homopolymers. Moreover, hnRNP M is able to interact with early spliceosomes, further influencing splicing patterns of specific pre-mRNAs. hnRNP M functions as the receptor of carcinoembryonic antigen (CEA) that contains the penta-peptide sequence PELPK signaling motif. In addition, hnRNP M and another splicing factor Nova-1 work together as dopamine D2 receptor (D2R) pre-mRNA-binding proteins. They regulate alternative splicing of D2R pre-mRNA in an antagonistic manner. hnRNP M contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an unusual hexapeptide-repeat region rich in methionine and arginine residues (MR repeat motif).

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGfCfGFVEFETSSGKQSA 350
Cdd:cd12661   2 IFVRNLPFDFTWKMLKDKFNECGHVLYADIKMENGKSKG-C-GVVRFESPEVAERA 55

RNA recognition motif 2 (RRM2) found in granule-associated RNA binding proteins (p40-TIA-1 and TIAR), and yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1; This subfamily corresponds to the RRM3 of TIA-1, TIAR, and PUB1. Nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR) are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. They share high sequence similarity and are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis.TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both TIA-1 and TIAR bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains. This subfamily also includes a yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1, termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein, which has been identified as both a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP). It may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. PUB1 is distributed in both, the nucleus and the cytoplasm, and binds to poly(A)+ RNA (mRNA or pre-mRNA). Although it is one of the major cellular proteins cross-linked by UV light to polyadenylated RNAs in vivo, PUB1 is nonessential for cell growth in yeast. PUB1 also binds to T-rich single stranded DNA (ssDNA); however, there is no strong evidence implicating PUB1 in the mechanism of DNA replication. PUB1 contains three RRMs, and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455 294 SIYVRNLPFDSTPTQLEEVFKNFGAIKhegiQVRSNKQQGFCfgFVEFETssgKQSALEA 353
Cdd:cd12354   2 TVYVGNITKGLTEALLQQTFSPFGQIL----EVRVFPDKGYA--FIRFDS---HEAATHA 52

RNA recognition motif 3 (RRM3) found in Drosophila melanogaster Bruno protein and similar proteins; This subgroup corresponds to the RRM3 of Bruno protein, a Drosophila RNA recognition motif (RRM)-containing protein that plays a central role in regulation of Oskar (Osk) expression. It mediates repression by binding to regulatory Bruno response elements (BREs) in the Osk mRNA 3' UTR. The full-length Bruno protein contains three RRMs, two located in the N-terminal half of the protein and the third near the C-terminus, separated by a linker region.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30697455 291 DGHSIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:cd12640   3 EGCNLFIYHLPQEFTDTDLAQTFLPFGNVISAKVFIDKQTNLSKCFGFVSYDNPDSAQAAIQA 65

RNA recognition motif (RRM) found in nucleolar protein 8 (NOL8) and similar proteins; This model corresponds to the RRM of NOL8 (also termed Nop132) encoded by a novel NOL8 gene that is up-regulated in the majority of diffuse-type, but not intestinal-type, gastric cancers. Thus, NOL8 may be a good molecular target for treatment of diffuse-type gastric cancer. Also, NOL8 is a phosphorylated protein that contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), suggesting NOL8 is likely to function as a novel RNA-binding protein. It may be involved in regulation of gene expression at the post-transcriptional level or in ribosome biogenesis in cancer cells.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKH-EGIQVRSNKQQGfcFGFVEFETS 344
Cdd:cd12226   2 LFVGGLSPSITEDDLERRFSRFGTVSDvEIIRKKDAPDRG--FAYIDLRTS 50

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

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIqVRSNKQQGFCFGFVEFET 343
Cdd:cd12412   3 NRIFVGGIDWDTTEEELREFFSKFGKVKDVKI-IKDRAGVSKGYGFVTFET 52

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
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIkhEGIQVRSNKQQGFC--FGFVEFETSSGKQSALE 352
Cdd:cd12284   1 LYVGSLHFNITEDMLRGIFEPFGKI--EFVQLQKDPETGRSkgYGFIQFRDAEDAKKALE 58

RNA recognition motif 2 (RRM2) found in the U1A/U2B"/SNF protein family; This subfamily corresponds to the RRM2 of U1A/U2B"/SNF protein family, containing Drosophila sex determination protein SNF and its two mammalian counterparts, U1 small nuclear ribonucleoprotein A (U1 snRNP A or U1-A or U1A) and U2 small nuclear ribonucleoprotein B" (U2 snRNP B" or U2B"), all of which consist of two RNA recognition motifs (RRMs) connected by a variable, flexible linker. SNF is an RNA-binding protein found in the U1 and U2 snRNPs of Drosophila where it is essential in sex determination and possesses a novel dual RNA binding specificity. SNF binds with high affinity to both Drosophila U1 snRNA stem-loop II (SLII) and U2 snRNA stem-loop IV (SLIV). It can also bind to poly(U) RNA tracts flanking the alternatively spliced Sex-lethal (Sxl) exon, as does Drosophila Sex-lethal protein (SXL). U1A is an RNA-binding protein associated with the U1 snRNP, a small RNA-protein complex involved in pre-mRNA splicing. U1A binds with high affinity and specificity to stem-loop II (SLII) of U1 snRNA. It is predominantly a nuclear protein that shuttles between the nucleus and the cytoplasm independently of interactions with U1 snRNA. Moreover, U1A may be involved in RNA 3'-end processing, specifically cleavage, splicing and polyadenylation, through interacting with a large number of non-snRNP proteins. U2B", initially identified to bind to stem-loop IV (SLIV) at the 3' end of U2 snRNA, is a unique protein that comprises of the U2 snRNP. Additional research indicates U2B" binds to U1 snRNA stem-loop II (SLII) as well and shows no preference for SLIV or SLII on the basis of binding affinity. U2B" does not require an auxiliary protein for binding to RNA and its nuclear transport is independent on U2 snRNA binding.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKhegiQVRSNKQQGfcFGFVEFETSSGKQSALEA 353
Cdd:cd12247   3 KILFLQNLPEETTKEMLEMLFNQFPGFK----EVRLVPRRG--IAFVEFETEEQATVALQA 57

RNA recognition motif 2 (RRM2) found in U2 large nuclear ribonucleoprotein auxiliary factor U2AF 65 kDa subunit (U2AF65) and similar proteins; This subfamily corresponds to the RRM2 of U2AF65 and dU2AF50. U2AF65, also termed U2AF2, is the large subunit of U2 small nuclear ribonucleoprotein (snRNP) auxiliary factor (U2AF), which has been implicated in the recruitment of U2 snRNP to pre-mRNAs and is a highly conserved heterodimer composed of large and small subunits. U2AF65 specifically recognizes the intron polypyrimidine tract upstream of the 3' splice site and promotes binding of U2 snRNP to the pre-mRNA branchpoint. U2AF65 also plays an important role in the nuclear export of mRNA. It facilitates the formation of a messenger ribonucleoprotein export complex, containing both the NXF1 receptor and the RNA substrate. Moreover, U2AF65 interacts directly and specifically with expanded CAG RNA, and serves as an adaptor to link expanded CAG RNA to NXF1 for RNA export. U2AF65 contains an N-terminal RS domain rich in arginine and serine, followed by a proline-rich segment and three C-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The N-terminal RS domain stabilizes the interaction of U2 snRNP with the branch point (BP) by contacting the branch region, and further promotes base pair interactions between U2 snRNA and the BP. The proline-rich segment mediates protein-protein interactions with the RRM domain of the small U2AF subunit (U2AF35 or U2AF1). The RRM1 and RRM2 are sufficient for specific RNA binding, while RRM3 is responsible for protein-protein interactions. The family also includes Splicing factor U2AF 50 kDa subunit (dU2AF50), the Drosophila ortholog of U2AF65. dU2AF50 functions as an essential pre-mRNA splicing factor in flies. It associates with intronless mRNAs and plays a significant and unexpected role in the nuclear export of a large number of intronless mRNAs.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKheGIQVRSNKQQGFC--FGFVEFETSSGKQSALEA-SPVTIGDRQAVV 365
Cdd:cd12231   1 NKLFIGGLPNYLNEDQVKELLQSFGKLK--AFNLVKDSATGLSkgYAFCEYVDDNVTDQAIAGlNGMQLGDKKLLV 74

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

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKH--EGIQVRSNKQQGFCfgFVEFETSSGKQSALEASPVTIGDRQAV 364
Cdd:cd12240   1 LYVGNLSFYTTEEQIYELFSKCGDIKRiiMGLDKFKKTPCGFC--FVEYYSREDAENAVKYLNGTKLDDRII 70

RNA recognition motif 1 (RRM1) found in plant polypyrimidine tract-binding protein homolog 1 and 2 (PTBPH1 and PTBPH2); This subfamily corresponds to the RRM1 of PTBPH1 and PTBPH2. Although their biological roles remain unclear, PTBPH1 and PTBPH2 show significant sequence similarity to polypyrimidine tract binding protein (PTB) that is an important negative regulator of alternative splicing in mammalian cells and also functions at several other aspects of mRNA metabolism, including mRNA localization, stabilization, polyadenylation, and translation. Both, PTBPH1 and PTBPH2, contain three RNA recognition motifs (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*...
gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQgfcfGFVEFE 342
Cdd:cd12686   5 LHLRNLPWECTEEELIELCKPFGTVVNTKCNVGANKNQ----AFVEFA 48

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30697455   293 HSIYVRNLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETSSGKQSALEA 353
Cdd:TIGR01622 215 HRLYVGNLHFNITEQDLRQIFEPFGEIEFVQLQKDPETGRSKGYGFIQFRDAEQAKEALEK 275

RNA recognition motif 4 (RRM4) found in heterogeneous nuclear ribonucleoprotein L (hnRNP-L) and similar proteins; This subfamily corresponds to the RRM4 of heterogeneous nuclear ribonucleoprotein L (hnRNP-L), heterogeneous nuclear ribonucleoprotein L-like (hnRNP-LL), and similar proteins. hnRNP-L is a higher eukaryotic specific subunit of human KMT3a (also known as HYPB or hSet2) complex required for histone H3 Lys-36 trimethylation activity. It plays both, nuclear and cytoplasmic, roles in mRNA export of intronless genes, IRES-mediated translation, mRNA stability, and splicing. hnRNP-LL plays a critical and unique role in the signal-induced regulation of CD45 and acts as a global regulator of alternative splicing in activated T cells. It is closely related in domain structure and sequence to hnRNP-L, which contains three RNA-recognition motifs (RRMs), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

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                ....*....|....*....|....*....|....*....|....*....|....*
gi 30697455 299 NLPFDSTPTQLEEVFKNFGAIKHEGIQVRSNKQQGFCFGFVEFETssgKQSALEA 353
Cdd:cd12427   9 NAPPEITEETLKELFIEAGAPPPVKVKVFPSKSERSSSGLLEFES---VEDALEA 60

RNA recognition motif 1 (RRM1) found in chloroplastic plastid-specific 30S ribosomal protein 2 (PSRP-2) and similar proteins; PSRP-2, also called chloroplastic 30S ribosomal protein 2, or chloroplastic small ribosomal subunit protein cS22, is a component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus. It binds single strand DNA (ssDNA) and RNA in vitro. It exhibits RNA chaperone activity and regulates negatively resistance responses to abiotic stresses during seed germination (e.g. salt, dehydration, and low temperature) and seedling growth (e.g. salt). The family also includes Nicotiana sylvestris chloroplastic 33 kDa ribonucleoprotein (NsCP33) and Arabidopsis thaliana chloroplastic 31 kDa ribonucleoprotein (AtCP31A). 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. 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 first RRM motif.

                        10        20        30        40        50        60
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gi 30697455 295 IYVRNLPFDSTPTQLEEVFKNFGAIkhEGIQVRSNKQQGFC--FGFVEFETSSGKQSALE 352
Cdd:cd21609   2 LYVGNIPRNVTSEELAKIFEEAGTV--EIAEVMYDRYTGRSrgFGFVTMGSVEDAKAAIE 59

RNA recognition motif 2 (RRM2) found in tRNA selenocysteine-associated protein 1 (SECp43) and similar proteins; This subfamily corresponds to the RRM2 in tRNA selenocysteine-associated protein 1 (SECp43), yeast negative growth regulatory protein NGR1 (RBP1), yeast protein NAM8, and similar proteins. SECp43 is an RNA-binding protein associated specifically with eukaryotic selenocysteine tRNA [tRNA(Sec)]. It may play an adaptor role in the mechanism of selenocysteine insertion. SECp43 is located primarily in the nucleus and contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal polar/acidic region. Yeast proteins, NGR1 and NAM8, show high sequence similarity with SECp43. NGR1 is a putative glucose-repressible protein that binds both RNA and single-stranded DNA (ssDNA). It may function in regulating cell growth in early log phase, possibly through its participation in RNA metabolism. NGR1 contains three RRMs, two of which are followed by a glutamine-rich stretch that may be involved in transcriptional activity. In addition, NGR1 has an asparagine-rich region near the C-terminus which also harbors a methionine-rich region. NAM8 is a putative RNA-binding protein that acts as a suppressor of mitochondrial splicing deficiencies when overexpressed in yeast. It may be a non-essential component of the mitochondrial splicing machinery. NAM8 also contains three RRMs.

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gi 30697455 293 HSIYVRNLPFDSTPTQLEEVFKN-FGAIKheGIQVRSNKQQGF--CFGFVEFETSSGKQSAL-EASPVTIGDR 361
Cdd:cd12345   2 HSLFVGDLAPDVTDYQLYETFSArYPSVR--GAKVVMDPVTGRskGYGFVRFGDESEQDRALtEMQGVYLGSR 72