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 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAKRATGEklvlCFVEFMDAKCAATALEALQGYKFD 203
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRLVRDETGRSKGF----AFVEFEDEEDAEKAIEALNGKELG 65

U2 snRNP auxilliary factor, large subunit, splicing factor; These splicing factors consist of an N-terminal arginine-rich low complexity domain followed by three tandem RNA recognition motifs (pfam00076). The well-characterized members of this family are auxilliary components of the U2 small nuclear ribonuclearprotein splicing factor (U2AF). These proteins are closely related to the CC1-like subfamily of splicing factors (TIGR01622). Members of this subfamily are found in plants, metazoa and fungi.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1376934198 130 DASSTLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVhKDakRATGEKLVLCFVEFMDAKCAATALEALQGYKFDEN 205
Cdd:TIGR01642 293 DSKDRIYIGNLPLYLGEDQIKELLESFGDLKAFNLI-KD--IATGLSKGYAFCEYKDPSVTDVAIAALNGKDTGDN 365

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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1376934198 132 SSTLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVhkdAKRAtgeklvLCFVEFMDAKCAATALEALQGYKFDENDP 207
Cdd:cd12247     2 NKILFLQNLPEETTKEMLEMLFNQFPGFKEVRLV---PRRG------IAFVEFETEEQATVALQALQGFKITPGHA 68

RNA recognition motif (RRM) found in yeast cell wall integrity protein scw1 and similar proteins; This subfamily corresponds to the RRM of the family including yeast cell wall integrity protein scw1, yeast Whi3 protein, yeast Whi4 protein and similar proteins. The strong cell wall protein 1, scw1, is a nonessential cytoplasmic RNA-binding protein that regulates septation and cell-wall structure in fission yeast. It may function as an inhibitor of septum formation, such that its loss of function allows weak SIN signaling to promote septum formation. It's RRM domain shows high homology to two budding yeast proteins, Whi3 and Whi4. Whi3 is a dose-dependent modulator of cell size and has been implicated in cell cycle control in the yeast Saccharomyces cerevisiae. It functions as a negative regulator of ceroid-lipofuscinosis, neuronal 3 (Cln3), a G1 cyclin that promotes transcription of many genes to trigger the G1/S transition in budding yeast. It specifically binds the CLN3 mRNA and localizes it into discrete cytoplasmic loci that may locally restrict Cln3 synthesis to modulate cell cycle progression. Moreover, Whi3 plays a key role in cell fate determination in budding yeast. The RRM domain is essential for Whi3 function. Whi4 is a partially redundant homolog of Whi3, also containing one RRM. Some uncharacterized family members of this subfamily contain two RRMs; their RRM1 shows high sequence homology to the RRM of RNA-binding protein with multiple splicing (RBP-MS)-like proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 133 STLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDakratgeKLVLCFVEFMDAKCAATALEALQGYKFDENDPDSyvL 212
Cdd:cd12245     3 NTLFVANLGPNVSEQELRQLFSRQPGFRRLRMHNKG-------GGPVCFVEFEDVPFATQALNHLQGAILSSSDRGG--I 73

                  ....*.
gi 1376934198 213 RLTFAR 218
Cdd:cd12245    74 RIEYAK 79

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198  134 TLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHkdaKRATGEKLVLCFVEFMDAKCAATALEALQGYKFD 203
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVR---DKETGKSKGFAFVEFESEEDAEKALEALNGKELD 67

RNA recognition motif 2 (RRM2) found in squamous cell carcinoma antigen recognized by T-cells 3 (SART3) and similar proteins; This subfamily corresponds to the RRM2 of SART3, also termed Tat-interacting protein of 110 kDa (Tip110), is 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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAKRATGeklvLCFVEFMDAKCAATALEALQGYKFDEN 205
Cdd:cd12392     4 KLFVKGLPFSCTKEELEELFKQHGTVKDVRLVTYRNGKPKG----LAYVEYENEADASQAVLKTDGTEIKDH 71

RNA recognition motif (RRM) found in vertebrate RNA-binding protein with multiple splicing 2 (RBP-MS2); This subfamily corresponds to the RRM of RBP-MS2, encoded by RBPMS2 gene, a paralog of RNA-binding protein with multiple splicing (RBP-MS). The biological function of RBP-MS2 remains unclear. Like RBP-MS, RBP-MS2 contains an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFkEVRLVHKDAKRATGeklvlcFVEFMDAKCAATALEALQGYKFDENDPDSyvLR 213
Cdd:cd12683     3 TLFVSGLPVDIKPRELYLLFRPFKGY-EGSLIKLTSKQPVG------FVTFDSRAGAEAAKNALNGIRFDPENPQT--LR 73

                  ...
gi 1376934198 214 LTF 216
Cdd:cd12683    74 LEF 76

RNA recognition motif (RRM) found in Drosophila couch potato (cpo) coding RNA-binding protein and similar proteins; This subfamily corresponds to the RRM of Cpo, an RNA-binding protein encoded by Drosophila couch potato (cpo) gene. Cpo contains a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It may control the processing of RNA molecules required for the proper functioning of the peripheral nervous system (PNS).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFK--EVRLVHKDAKRATGeklvLCFVEFMDAKCAATALEALQGYKFDENDPDsyV 211
Cdd:cd12684     3 TLFVSGLPMDAKPRELYLLFRAYKGYEgsLLKVTSKNGKTTSP----VGFVTFLSRQAAEAAKQDLQGVRFDPDLPQ--T 76

                  ....*..
gi 1376934198 212 LRLTFAR 218
Cdd:cd12684    77 LRLEFAK 83

RNA recognition motif 2 (RRM2) found in vertebrate U1 small nuclear ribonucleoprotein A (U1 snRNP A or U1-A or U1A); This subgroup corresponds to the RRM2 of U1A (also termed U1 snRNP A or U1-A), 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. U1A may be involved in RNA 3'-end processing, specifically cleavage, splicing and polyadenylation, through interacting with a large number of non-snRNP proteins, including polypyrimidine tract binding protein (PTB), polypyrimidine-tract binding protein-associated factor (PSF), and non-POU-domain-containing, octamer-binding (NONO), DEAD (Asp-Glu-Ala-Asp) box polypeptide 5 (DDX5). U1A also binds to a flavivirus NS5 protein and plays an important role in virus replication. It contains two RNA recognition motifs (RRMs); the N-terminal RRM (RRM1) binds tightly and specifically to the U1 snRNA SLII and its own 3'-UTR, while in contrast, the C-terminal RRM (RRM2) does not appear to associate with any RNA and it may be free for binding other proteins. U1A also contains a proline-rich region, and a nuclear localization signal (NLS) in the central domain that is responsible for its nuclear import.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKdakratgeKLVLCFVEFMDAKCAATALEALQGYKFDENDpdsyVLRL 214
Cdd:cd12480    14 LFLTNLPEETNELMLSMLFNQFPGFKEVRLVPG--------RHDIAFVEFDNEVQAGAAREALQGFKITQSN----AMKI 81

                  ....
gi 1376934198 215 TFAR 218
Cdd:cd12480    82 SFAK 85

RNA recognition motif 4 (RRM4) found in yeast multiple RNA-binding domain-containing protein 1 (MRD1) and similar proteins; This subfamily corresponds to the RRM4 of MRD1which 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). MRD1 is essential for the initial processing at the A0-A2 cleavage sites in the 35 S pre-rRNA. It 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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1376934198 133 STLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAKRATGEKLVL--CFVEFMDAKCAATALEALQGYKFD 203
Cdd:cd12319     1 ATLFVKNLNFSTTNQHLTDVFKHLDGFVFARVKTKPDPKRPGKTLSMgfGFVGFKTKEQAQAALKAMDGFVLD 73

RNA recognition motif 1 (RRM1) found in the Hu proteins family, Drosophila sex-lethal (SXL), and similar proteins; This subfamily corresponds to the RRM1 of Hu proteins and SXL. The Hu proteins family represents 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 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. This family also includes the sex-lethal protein (SXL) from Drosophila melanogaster. SXL governs sexual differentiation and X chromosome dosage compensation in flies. It induces female-specific alternative splicing of the transformer (tra) pre-mRNA by binding to the tra uridine-rich polypyrimidine tract at the non-sex-specific 3' splice site during the sex-determination process. SXL binds to its own pre-mRNA and promotes female-specific alternative splicing. It contains an N-terminal Gly/Asn-rich domain that may be responsible for the protein-protein interaction, and tandem RRMs that show high preference to bind single-stranded, uridine-rich target RNA transcripts.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKdakRATGEKLVLCFVEFMDAKCAATALEALQGYK 201
Cdd:cd12375     2 LIVNYLPQSMTQEELRSLFGAIGPIESCKLVRD---KITGQSLGYGFVNYRDPNDARKAINTLNGLD 65

RNA recognition motif 1 (RRM1) found in plant pre-mRNA-splicing factor SF2 and similar proteins; This subgroup corresponds to the RRM1 of SF2, also termed SR1 protein, a plant serine/arginine (SR)-rich phosphoprotein similar to the mammalian splicing factor SF2/ASF. It promotes splice site switching in mammalian nuclear extracts. SF2 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal domain rich in proline, serine and lysine residues (PSK domain), a composition reminiscent of histones. This PSK domain harbors a putative phosphorylation site for the mitotic kinase cyclin/p34cdc2.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFrpfigFKEVRLVHKDAK---RATGeklvLCFVEFMDAKCAATALEALQGYKFDEN 205
Cdd:cd12599     1 RVYVGNLPMDIREREVEDLF-----SKYGPVVSIDLKippRPPA----YAFVEFEDARDAEDAIRGRDGYDFDGH 66

RNA recognition motif 1 (RRM1) found in yeast nucleolar protein 3 (Npl3p) and similar proteins; This subfamily corresponds to the RRM1 of Npl3p, also termed mitochondrial targeting suppressor 1 protein, or nuclear polyadenylated RNA-binding protein 1. Npl3p is a major yeast RNA-binding protein that competes with 3'-end processing factors, such as Rna15, for binding to the nascent RNA, protecting the transcript from premature termination and coordinating transcription termination and the packaging of the fully processed transcript for export. It specifically recognizes a class of G/U-rich RNAs. Npl3p is a multi-domain protein containing two central RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), separated by a short linker and a C-terminal domain rich in glycine, arginine and serine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAKRatgeklvlcFVEFMDAKCAATALEALQGyKFDENDP 207
Cdd:cd12340     2 LFVRPFPPDTSESAIREIFSPYGPVKEVKMLSDSNFA---------FVEFEELEDAIRAKDSVHG-RVLNNEP 64

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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1376934198 132 SSTLFVDGLPSDCTRREAAHIFRPFigfKEVRLVHKDAKRATGEKLVLCFVEFMDAKCAATALEALQGYKF 202
Cdd:cd12566     2 TGRLFLRNLPYSTKEDDLQKLFSKF---GEVSEVHVPIDKKTKKSKGFAYVLFLDPEDAVQAYNELDGKVF 69

RNA recognition motif (RRM) found in eukaryotic translation initiation factor 3 subunit G (eIF-3G) and similar proteins; This subfamily corresponds to the RRM of eIF-3G and similar proteins. eIF-3G, also termed eIF-3 subunit 4, or eIF-3-delta, or eIF3-p42, or eIF3-p44, is the RNA-binding subunit of eIF3, a large multisubunit complex that plays a central role in the initiation of translation by binding to the 40 S ribosomal subunit and promoting the binding of methionyl-tRNAi and mRNA. eIF-3G binds 18 S rRNA and beta-globin mRNA, and therefore appears to be a nonspecific RNA-binding protein. eIF-3G is one of the cytosolic targets and interacts with mature apoptosis-inducing factor (AIF). eIF-3G contains one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). This family also includes yeast eIF3-p33, a homolog of vertebrate eIF-3G, plays an important role in the initiation phase of protein synthesis in yeast. It binds both, mRNA and rRNA, fragments due to an RRM near its C-terminus.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVhKDakRATGEKLVLCFVEFMDAKCAATALEALQGYKFD 203
Cdd:cd12408     1 TIRVTNLSEDATEEDLRELFRPFGPISRVYLA-KD--KETGQSKGFAFVTFETREDAERAIEKLNGFGYD 67

RNA recognition motif 1 (RRM1) found in vertebrate Hu-antigen B (HuB); This subgroup corresponds to the RRM1 of HuB, also termed ELAV-like protein 2 (ELAV-2), or ELAV-like neuronal protein 1, or nervous system-specific RNA-binding protein Hel-N1 (Hel-N1), one of the neuronal members of the Hu family. The neuronal Hu proteins play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads and is up-regulated during neuronal differentiation of embryonic carcinoma P19 cells. Like other Hu proteins, HuB 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 AU-rich RNA element (ARE). RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1376934198 130 DASSTLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKdakRATGEKLVLCFVEFMDAKCAATALEALQGYKFdendpDS 209
Cdd:cd12771     2 DSKTNLIVNYLPQNMTQEELKSLFGSIGEIESCKLVRD---KITGQSLGYGFVNYIEPKDAEKAINTLNGLRL-----QT 73

                  ....*....
gi 1376934198 210 YVLRLTFAR 218
Cdd:cd12771    74 KTIKVSYAR 82

RNA recognition motif 3 (RRM3) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM3 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFKEVRLV-HKDAKRATGeklvLCFVEFMDAKCAATALEA 196
Cdd:cd12415     2 TVFIRNLSFDTTEEDLKEFFSKFGEVKYARIVlDKDTGHSKG----TAFVQFKTKESADKCIEA 61

RNA recognition motif (RRM) found in eukaryotic translation initiation factor 3 subunit B (eIF-3B) and similar proteins; This subfamily corresponds to the RRM domain in eukaryotic translation initiation factor 3 (eIF-3), a large multisubunit complex that plays a central role in the initiation of translation by binding to the 40 S ribosomal subunit and promoting the binding of methionyl-tRNAi and mRNA. eIF-3B, also termed eIF-3 subunit 9, or Prt1 homolog, eIF-3-eta, eIF-3 p110, or eIF-3 p116, is the major scaffolding subunit of eIF-3. It interacts with eIF-3 subunits A, G, I, and J. eIF-3B contains an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is involved in the interaction with eIF-3J. The interaction between eIF-3B and eIF-3J is crucial for the eIF-3 recruitment to the 40 S ribosomal subunit. eIF-3B also binds directly to domain III of the internal ribosome-entry site (IRES) element of hepatitis-C virus (HCV) RNA through its N-terminal RRM, which may play a critical role in both cap-dependent and cap-independent translation. Additional research has shown that eIF-3B may function as an oncogene in glioma cells and can be served as a potential therapeutic target for anti-glioma therapy. This family also includes the yeast homolog of eIF-3 subunit B (eIF-3B, also termed PRT1 or eIF-3 p90) that interacts with the yeast homologs of eIF-3 subunits A(TIF32), G(TIF35), I(TIF34), J(HCR1), and E(Pci8). In yeast, eIF-3B (PRT1) contains an N-terminal RRM that is directly involved in the interaction with eIF-3A (TIF32) and eIF-3J (HCR1). In contrast to its human homolog, yeast eIF-3B (PRT1) may have potential to bind its total RNA through its RRM domain.

                          10        20
                  ....*....|....*....|....*..
gi 1376934198 179 LCFVEFMDAKCAATALEALQGYKFDEN 205
Cdd:cd12278    52 FAFVEYATPEEAKKAVKALNGYKLDKK 78

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 1376934198 133 STLFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAkrATGEKLVLCFVEFMDAKCAATALEALQ 198
Cdd:cd12571     1 SKILVRNIPFQATVKEVRELFSTFGELKTVRLPKKMG--GTGQHRGFGFVDFITKQDAKRAFDALC 64

RNA recognition motif 1 (RRM1) and 2 (RRM2) found in CELF/Bruno-like family of RNA binding proteins and plant flowering time control protein FCA; This subfamily corresponds to the RRM1 and RRM2 domains of the CUGBP1 and ETR-3-like factors (CELF) as well as plant flowering time control protein FCA. CELF, also termed BRUNOL (Bruno-like) proteins, is a family of structurally related RNA-binding proteins involved in regulation of pre-mRNA splicing in the nucleus, and control of mRNA translation and deadenylation in the cytoplasm. The family contains six members: CELF-1 (also known as BRUNOL-2, CUG-BP1, NAPOR, EDEN-BP), CELF-2 (also known as BRUNOL-3, ETR-3, CUG-BP2, NAPOR-2), CELF-3 (also known as BRUNOL-1, TNRC4, ETR-1, CAGH4, ER DA4), CELF-4 (BRUNOL-4), CELF-5 (BRUNOL-5) and CELF-6 (BRUNOL-6). They all contain three highly conserved RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains): two consecutive RRMs (RRM1 and RRM2) situated in the N-terminal region followed by a linker region and the third RRM (RRM3) close to the C-terminus of the protein. The low sequence conservation of the linker region is highly suggestive of a large variety in the co-factors that associate with the various CELF family members. Based on both, sequence similarity and function, the CELF family can be divided into two subfamilies, the first containing CELFs 1 and 2, and the second containing CELFs 3, 4, 5, and 6. The different CELF proteins may act through different sites on at least some substrates. Furthermore, CELF proteins may interact with each other in varying combinations to influence alternative splicing in different contexts. This subfamily also includes plant flowering time control protein FCA that functions in the posttranscriptional regulation of transcripts involved in the flowering process. FCA contains two RRMs, and a WW protein interaction domain.

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gi 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVhKDakRATGEKLVLCFVEFMDAKCAATALEALQG 199
Cdd:cd12361     2 LFVGMIPKTASEEDVRPLFEQFGNIEEVQIL-RD--KQTGQSKGCAFVTFSTREEALRAIEALHN 63

RNA recognition motif 1 (RRM1) found in serine/arginine-rich splicing factor 1 (SRSF1) and similar proteins; This subgroup corresponds to the RRM1 in three serine/arginine (SR) proteins: serine/arginine-rich splicing factor 1 (SRSF1 or ASF-1), serine/arginine-rich splicing factor 9 (SRSF9 or SRp30C), and plant pre-mRNA-splicing factor SF2 (SR1). SRSF1 is a shuttling SR protein involved in constitutive and alternative splicing, nonsense-mediated mRNA decay (NMD), mRNA export and translation. It also functions as a splicing-factor oncoprotein that regulates apoptosis and proliferation to promote mammary epithelial cell transformation. SRSF9 has been implicated in the activity of many elements that control splice site selection, the alternative splicing of the glucocorticoid receptor beta in neutrophils and in the gonadotropin-releasing hormone pre-mRNA. It can also interact with other proteins implicated in alternative splicing, including YB-1, rSLM-1, rSLM-2, E4-ORF4, Nop30, and p32. Both, SRSF1 and SRSF9, contain two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal RS domains rich in serine-arginine dipeptides. In contrast, SF2 contains two N-terminal RRMs and a C-terminal PSK domain rich in proline, serine and lysine residues.

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gi 1376934198 134 TLFVDGLPSDCTRREAAHIFRPFIGFKEVRLvhKDAKRATGeklvLCFVEFMDAKCAATALEALQGYKFD 203
Cdd:cd12338     1 RIYVGNLPGDIRERDIEDLFYKYGPILAIDL--KNRRRGPP----FAFVEFEDPRDAEDAIRGRDGYDFD 64

RNA recognition motif 2 (RRM2) found in plant flowering time control protein FCA and similar proteins; This subgroup corresponds to the RRM2 of FCA, a gene controlling flowering time in Arabidopsis, which encodes a flowering time control protein that functions in the posttranscriptional regulation of transcripts involved in the flowering process. The flowering time control protein FCA contains two RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNP (ribonucleoprotein domains), and a WW protein interaction domain.

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gi 1376934198 135 LFVDGLPSDCTRREAAHIFRPFIGFKEVRLVHKDAKRA-TGeklvLCFVEFMDAKCAATALEALQG-YKFD 203
Cdd:cd12637     2 LFVGSLPKTATEQEVRDLFEAYGEVEEVYLMKDPVTQQgTG----CAFVKFAYKEEALAAIRSLNGtVTFD 68