RNA recognition motif 2 (RRM2) found in tRNA selenocysteine-associated protein 1 (SECp43); This subgroup corresponds to the RRM2 of SECp43, 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  29 EYSLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGCKPVRLSVAI 108
Cdd:cd12612    1 EFSLFVGDLTPEVDDGMLYEFFLKRYPSCKGAKVVLDQLGNSRGYGFVRFSDENEQKRALTECQGASGLGGKPIRLSVAI 80

                 ..
gi 568931902 109 PK 110
Cdd:cd12612   81 PK 82

RNA recognition motif 2 (RRM2) found in tRNA selenocysteine-associated protein 1 (SECp43); This subgroup corresponds to the RRM2 of SECp43, 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  29 EYSLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGCKPVRLSVAI 108
Cdd:cd12612    1 EFSLFVGDLTPEVDDGMLYEFFLKRYPSCKGAKVVLDQLGNSRGYGFVRFSDENEQKRALTECQGASGLGGKPIRLSVAI 80

                 ..
gi 568931902 109 PK 110
Cdd:cd12612   81 PK 82

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 568931902   32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGCK 100
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSK-FGPIKSIRLVRDETGRSKGFAFVEFEDEEDAEKAIEALNGKELGGRE 68

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902   32 LFVGDLTPDVDDGMLYEFFvKVYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLSVAIPKA 111
Cdd:TIGR01628 288 LYVKNLDDTVTDEKLRELF-SECGEITSAKVMLDEKGVSRGFGFVCFSNPEEANRAVTEMHGRM-LGGKPLYVALAQRKE 365

                  ..
gi 568931902  112 SR 113
Cdd:TIGR01628 366 QR 367

glycine-rich RNA-binding protein 4; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTECQGAvGLGCKPVRLSVAIPK 110
Cdd:PLN03134  37 LFIGGLSWGTDDASLRDAFAH-FGDVVDAKVIVDrETGRSRGFGFVNFNDEGAATAAISEMDGK-ELNGRHIRVNPANDR 114

                 ..
gi 568931902 111 AS 112
Cdd:PLN03134 115 PS 116

RNA recognition motif 2 (RRM2) found in tRNA selenocysteine-associated protein 1 (SECp43); This subgroup corresponds to the RRM2 of SECp43, 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  29 EYSLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGCKPVRLSVAI 108
Cdd:cd12612    1 EFSLFVGDLTPEVDDGMLYEFFLKRYPSCKGAKVVLDQLGNSRGYGFVRFSDENEQKRALTECQGASGLGGKPIRLSVAI 80

                 ..
gi 568931902 109 PK 110
Cdd:cd12612   81 PK 82

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  29 EYSLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQGaVGLGCKPVRLSVA 107
Cdd:cd12345    1 EHSLFVGDLAPDVTDYQLYETFSARYPSVRGAKVVMDPvTGRSKGYGFVRFGDESEQDRALTEMQG-VYLGSRPIRVSPA 79

                 .
gi 568931902 108 I 108
Cdd:cd12345   80 T 80

RNA recognition motif 2 (RRM2) found in yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1 and similar proteins; This subgroup corresponds to the RRM2 of yeast protein PUB1, also termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein. PUB1 has been identified as both, a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP), which may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. It is distributed in both, the nucleus and the cytoplasm, and binds to poly(A)+ RNA (mRNA or pre-mRNA). Although it is one of the major cellular proteins cross-linked by UV light to polyadenylated RNAs in vivo, PUB1 is nonessential for cell growth in yeast. PUB1 also binds to T-rich single stranded DNA (ssDNA). However, there is no strong evidence implicating PUB1 in the mechanism of DNA replication. PUB1 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568931902  30 YSLFVGDLTPDVDDGMLYEFFvKVYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLSVA 107
Cdd:cd12619    2 FNIFVGDLSPEVTDAALFNAF-SDFPSCSDARVMWDqKTGRSRGYGFVSFRSQQDAQNAINSMNGKW-LGSRPIRCNWA 78

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 568931902   32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGCK 100
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSK-FGPIKSIRLVRDETGRSKGFAFVEFEDEEDAEKAIEALNGKELGGRE 68

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 568931902  32 LFVGDLTPDVDDGMLYEFFVKVYP--SCRggkVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLS 105
Cdd:cd00590    1 LFVGNLPPDTTEEDLRELFSKFGEvvSVR---IVRDRDGKSKGFAFVEFESPEDAEKALEALNGTE-LGGRPLKVS 72

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902   32 LFVGDLTPDVDDGMLYEFFvKVYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLSVAIPKA 111
Cdd:TIGR01628 288 LYVKNLDDTVTDEKLRELF-SECGEITSAKVMLDEKGVSRGFGFVCFSNPEEANRAVTEMHGRM-LGGKPLYVALAQRKE 365

                  ..
gi 568931902  112 SR 113
Cdd:TIGR01628 366 QR 367

RNA recognition motif 2 (RRM2) found in splicing factor 3B subunit 4 (SF3B4) and similar proteins; This subfamily corresponds to the RRM2 of SF3B4, also termed pre-mRNA-splicing factor SF3b 49 kDa (SF3b50), or spliceosome-associated protein 49 (SAP 49). SF3B4 is 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        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDP-TGVSKGYGFVKFtDELEQKRALTECQGAVGLGCKPVRLSVAIPK 110
Cdd:cd12335    4 LFIGNLDPEVDEKLLYDTFSAFGVILQTPKIMRDPdTGNSKGFGFVSF-DSFEASDAAIEAMNGQYLCNRPITVSYAFKK 82

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGcKPVRLSVAIPK 110
Cdd:cd12412    5 IFVGGIDWDTTEEELREFFSK-FGKVKDVKIIKDRAGVSKGYGFVTFETQEDAEKIQKWGANLVFKG-KKLNVGPAIRK 81

RNA recognition motif 4 (RRM4) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM4 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 theThe CD corresponds to the RRM. 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. Moreover, 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 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPvrLSVAI 108
Cdd:cd12381    4 LYVKNLDDTIDDEKLREEFSP-FGTITSAKVMTDEGGRSKGFGFVCFSSPEEATKAVTEMNGRI-IGGKP--LYVAL 76

RNA recognition motif 1 (RRM1) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM1 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 a 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. Moreover, 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 mammals, 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 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 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVYP--SCRggkVVLDP-TGVSKGYGFVKFTDELEQKRALTECQGAVGLGcKPVRL 104
Cdd:cd12378    1 SLYVGDLHPDVTEAMLYEKFSPAGPvlSIR---VCRDAvTRRSLGYAYVNFQQPADAERALDTLNFDVIKG-KPIRI 73

RNA recognition motif 2 (RRM2) found in Nicotiana sylvestris chloroplastic 33 kDa ribonucleoprotein (NsCP33) and similar proteins; The family includes NsCP33, Arabidopsis thaliana chloroplastic 31 kDa ribonucleoprotein (CP31A) and mitochondrial glycine-rich RNA-binding protein 2 (AtGR-RBP2). NsCP33 may be involved in splicing and/or processing of chloroplast RNA's. AtCP31A, also called RNA-binding protein 1/2/3 (AtRBP33), or RNA-binding protein CP31A, or RNA-binding protein RNP-T, or RNA-binding protein cp31, is required for specific RNA editing events in chloroplasts and stabilizes specific chloroplast mRNAs, as well as for normal chloroplast development under cold stress conditions by stabilizing transcripts of numerous mRNAs under these conditions. CP31A may modulate telomere replication through RNA binding domains. AtGR-RBP2, also called AtRBG2, or glycine-rich protein 2 (AtGRP2), or mitochondrial RNA-binding protein 1a (At-mRBP1a), plays a role in RNA transcription or processing during stress. It binds RNAs and DNAs sequence with a preference to single-stranded nucleic acids. AtGR-RBP2 displays strong affinity to poly(U) sequence. It exerts cold and freezing tolerance, probably by exhibiting an RNA chaperone activity during the cold and freezing adaptation process. Some members in this family contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLSVA 107
Cdd:cd21608    2 LYVGNLSWDTTEDDLRDLFSE-FGEVESAKVITDrETGRSRGFGFVTFSTAEAAEAAIDALNGKE-LDGRSIVVNEA 76

RNA recognition motif (RRM) found in protein BOULE; This subgroup corresponds to the RRM of BOULE, the founder member of the human DAZ gene family. Invertebrates contain a single BOULE, while vertebrates, other than catarrhine primates, possess both BOULE and DAZL genes. The catarrhine primates possess BOULE, DAZL, and DAZ genes. BOULE encodes an RNA-binding protein containing an RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a single copy of the DAZ motif. Although its specific biochemical functions remains to be investigated, BOULE protein may interact with poly(A)-binding proteins (PABPs), and act as translational activators of specific mRNAs during gametogenesis.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTE 90
Cdd:cd12673    4 RIFVGGIDFKTNENDLRKFFAQ-YGSVKEVKIVNDRAGVSKGYGFITFETQEDAQKILQE 62

RNA recognition motif 1 (RRM1) found in tRNA selenocysteine-associated protein 1 (SECp43); This subgroup corresponds to the RRM1 of SECp43, 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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQG 93
Cdd:cd12610    1 SLWMGDLEPYMDENFIKRAFATMGETVLSVKIIRNRvTGGPAGYCFVEFADEATAERCLHKLNG 64

RNA recognition motif 2 (RRM2) found in nucleolysin TIAR and similar proteins; This subgroup corresponds to the RRM2 of nucleolysin TIAR, also termed TIA-1-related protein, a cytotoxic granule-associated RNA-binding protein that shows high sequence similarity with 40-kDa isoform of T-cell-restricted intracellular antigen-1 (p40-TIA-1). 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. TIAR possesses nucleolytic activity against cytolytic lymphocyte (CTL) target cells. It can trigger DNA fragmentation in permeabilized thymocytes, and thus may function as an effector responsible for inducing apoptosis. TIAR is 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. It interacts with RNAs containing short stretches of uridylates and its RRM2 can mediate the specific binding to uridylate-rich RNAs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568931902  30 YSLFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTEcQGAVGLGCKPVRLSVA 107
Cdd:cd12617    2 FHVFVGDLSPEITTEDIKSAFAP-FGKISDARVVKDmATGKSKGYGFVSFYNKLDAENAIVH-MGGQWLGGRQIRTNWA 78

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
                 ....*....|....*....|....*....|....*....|....*....|.
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVYPsCRGGKVVLDPTGVSKGYGFVKFTDE 81
Cdd:cd12336    3 TLFVGNLDPRVTEEILYELFLQAGP-LEGVKIPKDPNGKPKNFAFVTFKHE 52

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

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  31 SLFVGDLTPDVDDGMLYEFF-----VKvypSCrggKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRL 104
Cdd:COG0724    3 KIYVGNLPYSVTEEDLRELFseygeVT---SV---KLITDReTGRSRGFGFVEMPDDEEAQAAIEALNGAE-LMGRTLKV 75

                 ....*....
gi 568931902 105 SVAIPKASR 113
Cdd:COG0724   76 NEARPREER 84

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        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVYPsCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQGAVGLGCKpVRLSVAIP 109
Cdd:cd12413    1 TLFVRNLPYDTTDEQLEELFSDVGP-VKRCFVVKDKgKDKCRGFGYVTFALAEDAQRALEEVKGKKFGGRK-IKVELAKK 78

                 .
gi 568931902 110 K 110
Cdd:cd12413   79 K 79

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQG 93
Cdd:cd12380    4 VYVKNFGEDVDDDELKELFEK-YGKITSAKVMKDDSGKSKGFGFVNFENHEAAQKAVEELNG 64

RNA recognition motif 2 (RRM2) found in nucleolysin TIA-1 isoform p40 (p40-TIA-1) and similar proteins; This subgroup corresponds to the RRM2 of p40-TIA-1, the 40-kDa isoform of T-cell-restricted intracellular antigen-1 (TIA-1), and a cytotoxic granule-associated RNA-binding protein mainly found in the granules of cytotoxic lymphocytes. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis, and function as the granule component responsible for inducing apoptosis in cytolytic lymphocyte (CTL) targets. It is 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 interacts with RNAs containing short stretches of uridylates and its RRM2 can mediate the specific binding to uridylate-rich RNAs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 568931902  30 YSLFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTEcQGAVGLGCKPVR 103
Cdd:cd12618    3 FHVFVGDLSPEITTEDIKAAFAP-FGRISDARVVKDmATGKSKGYGFVSFFNKWDAENAIQQ-MGGQWLGGRQIR 75

RNA recognition motif 1 (RRM1) found in tRNA selenocysteine-associated protein 1 (SECp43) and similar proteins; This subfamily corresponds to the RRM1 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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRAL 88
Cdd:cd12344    1 TLWMGDLEPWMDEAYISSCFAKTGEEVVSVKIIRNKqTGKSAGYCFVEFATQEAAEQAL 59

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTDELEQKRALTECQG 93
Cdd:cd12449    3 LFVGGLSFDTNEQSLEEVFSK-YGQISEVVVVKDrETQRSRGFGFVTFENPDDAKDAMMAMNG 64

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein hnRNP A and hnRNP D subfamilies and similar proteins; This subfamily corresponds to the RRM1 in the hnRNP A subfamily which includes hnRNP A0, hnRNP A1, hnRNP A2/B1, hnRNP A3 and similar proteins. hnRNP A0 is a low abundance hnRNP protein that has been implicated in mRNA stability in mammalian cells. hnRNP A1 is an abundant eukaryotic nuclear RNA-binding protein that may modulate splice site selection in pre-mRNA splicing. hnRNP A2/B1 is an RNA trafficking response element-binding protein that interacts with the hnRNP A2 response element (A2RE). hnRNP A3 is also a RNA trafficking response element-binding protein that participates in the trafficking of A2RE-containing RNA. The hnRNP A subfamily is characterized by two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long glycine-rich region at the C-terminus. The hnRNP D subfamily includes hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins. hnRNP D0 is a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP A/B is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus, plays an important role in apoB mRNA editing. hnRNP DL (or hnRNP D-like) is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. All members in this subfamily contain two putative RRMs and a glycine- and tyrosine-rich C-terminus. The family also contains DAZAP1 (Deleted in azoospermia-associated protein 1), RNA-binding protein Musashi homolog Musashi-1, Musashi-2 and similar proteins. They all harbor two RRMs.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRAL 88
Cdd:cd12325    1 LFVGGLSWETTEESLREYFSK-YGEVVDCVVMKDPaTGRSRGFGFVTFKDPSSVDAVL 57

RNA recognition motif 3 (RRM3) found in Schizosaccharomyces pombe mRNA export factor Crp79, meiotically up-regulated gene 28 protein (Mug28) and similar proteins; Crp79, also called meiotic expression up-regulated protein 5 (Mug5), or polyadenylate-binding protein crp79, or PABP, or poly(A)-binding protein, is an auxiliary mRNA export factor that binds the poly(A) tail of mRNA and is involved in the export of mRNA from the nucleus to the cytoplasm. Mug28 is a meiosis-specific protein that regulates spore wall formation. 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 three RRM motif.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 568931902  67 TGVSKGYGFVKFTDELEQKRALTECQGAVgLGCKPVRLSVAIPKASRVK 115
Cdd:cd21622   43 TGISKGFGFVAFSKPEDAAKAKETLNGVM-VGRKRIFVSYAERKEDREK 90

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 568931902   21 GKQPDNSPEYSLFVGDLTPDVDDGMLYEFFvKVYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQGaVGLGC 99
Cdd:TIGR01622 206 GHHPNSIPFHRLYVGNLHFNITEQDLRQIF-EPFGEIEFVQLQKDPeTGRSKGYGFIQFRDAEQAKEALEKMNG-FELAG 283

                  ....*...
gi 568931902  100 KPVRLSVA 107
Cdd:TIGR01622 284 RPIKVGLG 291

RNA recognition motif 1 (RRM1) found in squamous cell carcinoma antigen recognized by T-cells 3 (SART3) and similar proteins; This subfamily corresponds to the RRM1 of SART3, also termed Tat-interacting protein of 110 kDa (Tip110), an RNA-binding protein expressed in the nucleus of the majority of proliferating cells, including normal cells and malignant cells, but not in normal tissues except for the testes and fetal liver. It is involved in the regulation of mRNA splicing probably via its complex formation with RNA-binding protein with a serine-rich domain (RNPS1), a pre-mRNA-splicing factor. SART3 has also been identified as a nuclear Tat-interacting protein that regulates Tat transactivation activity through direct interaction and functions as an important cellular factor for HIV-1 gene expression and viral replication. In addition, SART3 is required for U6 snRNP targeting to Cajal bodies. It binds specifically and directly to the U6 snRNA, interacts transiently with the U6 and U4/U6 snRNPs, and promotes the reassembly of U4/U6 snRNPs after splicing in vitro. SART3 contains an N-terminal half-a-tetratricopeptide repeat (HAT)-rich domain, a nuclearlocalization signal (NLS) domain, and two C-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568931902  31 SLFVGDLTPDVDDGMLYEFFVKVypscrgGKV-----VLDPTGVSKGYGFVKFTDELEQKRALT 89
Cdd:cd12391    1 TVFVSNLDYSVPEDKIREIFSGC------GEItdvrlVKNYKGKSKGYCYVEFKDEESAQKALK 58

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDP-TGVSKGYGFVKFTDELEQKRALTECQG 93
Cdd:cd12236    4 LFVARLSYDTTESKLRREFEK-YGPIKRVRLVRDKkTGKSRGYAFIEFEHERDMKAAYKHADG 65

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
                 ....*....|....*....|....*....|....*....|....*....|
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDP-TGVSKGYGFVKFTD 80
Cdd:cd12377    2 IFVYNLAPDADESLLWQLFGP-FGAVQNVKIIRDFtTNKCKGYGFVTMTN 50

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568931902   26 NSPEYS-LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLDPTGVSKGYGFVKFTDELEQKRALTECQG-AVGLGCKPVR 103
Cdd:TIGR01628 174 PLKKFTnLYVKNLDPSVNEDKLRELFAK-FGEITSAAVMKDGSGRSRGFAFVNFEKHEDAAKAVEEMNGkKIGLAKEGKK 252

                          90
                  ....*....|..
gi 568931902  104 LSV--AIPKASR 113
Cdd:TIGR01628 253 LYVgrAQKRAER 264

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein A subfamily; This subfamily corresponds to the RRM2 of hnRNP A0, hnRNP A1, hnRNP A2/B1, hnRNP A3 and similar proteins. hnRNP A0 is a low abundance hnRNP protein that has been implicated in mRNA stability in mammalian cells. It has been identified as the substrate for MAPKAP-K2 and may be involved in the lipopolysaccharide (LPS)-induced post-transcriptional regulation of tumor necrosis factor-alpha (TNF-alpha), cyclooxygenase 2 (COX-2) and macrophage inflammatory protein 2 (MIP-2). hnRNP A1 is an abundant eukaryotic nuclear RNA-binding protein that may modulate splice site selection in pre-mRNA splicing. hnRNP A2/B1 is an RNA trafficking response element-binding protein that interacts with the hnRNP A2 response element (A2RE). Many mRNAs, such as myelin basic protein (MBP), myelin-associated oligodendrocytic basic protein (MOBP), carboxyanhydrase II (CAII), microtubule-associated protein tau, and amyloid precursor protein (APP) are trafficked by hnRNP A2/B1. hnRNP A3 is also a RNA trafficking response element-binding protein that participates in the trafficking of A2RE-containing RNA. The hnRNP A subfamily is characterized by two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long glycine-rich region at the C-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKvYPSCRGGKVVLD-PTGVSKGYGFVKFTD 80
Cdd:cd12328    2 LFVGGLKEDVEEEDLREYFSQ-FGKVESVEIVTDkETGKKRGFAFVTFDD 50

RNA recognition motif 1 (RRM1) found in the c-myc gene single-strand binding proteins (MSSP) family; This subfamily corresponds to the RRM1 of c-myc gene single-strand binding proteins (MSSP) family, including single-stranded DNA-binding protein MSSP-1 (also termed RBMS1 or SCR2) and MSSP-2 (also termed RBMS2 or SCR3). All MSSP family members contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), both of which are responsible for the specific DNA binding activity. Both, MSSP-1 and -2, have been identified as protein factors binding to a putative DNA replication origin/transcriptional enhancer sequence present upstream from the human c-myc gene in both single- and double-stranded forms. Thus, they have been implied in regulating DNA replication, transcription, apoptosis induction, and cell-cycle movement, via the interaction with c-MYC, the product of protooncogene c-myc. Moreover, the family includes a new member termed RNA-binding motif, single-stranded-interacting protein 3 (RBMS3), which is not a transcriptional regulator. RBMS3 binds with high affinity to A/U-rich stretches of RNA, and to A/T-rich DNA sequences, and functions as a regulator of cytoplasmic activity. In addition, a putative meiosis-specific RNA-binding protein termed sporulation-specific protein 5 (SPO5, or meiotic RNA-binding protein 1, or meiotically up-regulated gene 12 protein), encoded by Schizosaccharomyces pombe Spo5/Mug12 gene, is also included in this family. SPO5 is a novel meiosis I regulator that may function in the vicinity of the Mei2 dot.

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gi 568931902  32 LFVGDLTPDVDDGMLYEF---FVKVYPScrggKVVLDP-TGVSKGYGFVKFTDELEQKRALT 89
Cdd:cd12243    3 VYIRGLPPNTTDEDLLLLcqsFGKIIST----KAIIDKqTNKCKGYGFVDFDSPEAALKAIE 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.

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gi 568931902  61 KVVLDPTGVSKGYGFVKFTDELEQKRALTECQGAVGLGcKPVRLSVAI 108
Cdd:cd12414   30 TIPKKPDGKLRGFAFVQFTNVADAAKAIKGMNGKKIKG-RPVAVDWAV 76

RNA recognition motif 2 (RRM2) found in yeast protein gar2 and similar proteins; This subfamily corresponds to the RRM2 of yeast protein gar2, a novel nucleolar protein required for 18S rRNA and 40S ribosomal subunit accumulation. It shares similar domain architecture with nucleolin from vertebrates and NSR1 from Saccharomyces cerevisiae. The highly phosphorylated N-terminal domain of gar2 is made up of highly acidic regions separated from each other by basic sequences, and contains multiple phosphorylation sites. The central domain of gar2 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RGG (or GAR) domain of gar2 is rich in glycine, arginine and phenylalanine residues.

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gi 568931902  32 LFVGDLTPDVDDGMLYEFFVKV--YPSCRggkVVLDP-TGVSKGYGFVKFTDELEQKRAlTECQGAVGLGCKPVRLS 105
Cdd:cd12448    1 LFVGNLPFSATQDALYEAFSQHgsIVSVR---LPTDReTGQPKGFGYVDFSTIDSAEAA-IDALGGEYIDGRPIRLD 73