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 929653740   40 PPYTAYVGNLPFNTVQGDIDAIFKDLS-IRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVdiae 117
Cdd:TIGR01622 213 PFHRLYVGNLHFNITEQDLRQIFEPFGeIEFVQLQKDPETGRSKGYGFIQFRDAEQAKEALEkMNGFELAGRPIKV---- 288

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740  118 GRKQDKGGFGFRKGGPDDRGFRDDFLGGRGGSRPG--------DRRTGPPMGSRFRDGPPLRGSNM---------DFREP 180
Cdd:TIGR01622 289 GLGNDFTPESDANLAQRFQDQDGSAFSGAGLNTPArsqlmrklARDNEKGTGGLAIPGTDVGGVNMnnysrdglmRKLAP 368

                         170       180
                  ....*....|....*....|....*...
gi 929653740  181 TEEERAQRPRLQ-LKPRTVATPLNQVAN 207
Cdd:TIGR01622 369 TDEPPAVIPETQiLKPKAETSFVPVNVN 396

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRVDIAEGRKQ 121
Cdd:COG0724    5 YVGNLPYSVTEEDLRELFSEYgEVTSVKLITDRETGRSRGFGFVEMPDDEEAQAAIeALNGAELMGRTLKVNEARPREE 83

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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740   45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDkDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLR 112
Cdd:pfam00076   2 FVGNLPPDTTEEDLKDLFSKFgPIKSIRLVRD-ETGRSKGFAFVEFEDEEDAEKAIeALNGKELGGRELK 70

splicing factor, CC1-like family; This model represents a subfamily of RNA splicing factors including the Pad-1 protein (N. crassa), CAPER (M. musculus) and CC1.3 (H.sapiens). These proteins are characterized by an N-terminal arginine-rich, low complexity domain followed by three (or in the case of 4 H. sapiens paralogs, two) RNA recognition domains (rrm: pfam00706). These splicing factors are closely related to the U2AF splicing factor family (TIGR01642). A homologous gene from Plasmodium falciparum was identified in the course of the analysis of that genome at TIGR and was included in the seed.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 929653740   43 TAYVGNLPFNTVQGDIDAIFKDLS-IRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRVDIAEGRK 120
Cdd:TIGR01622 116 TVFVQQLAARARERDLYEFFSKVGkVRDVQIIKDRNSRRSKGVGYVEFYDVDSVQAALALTGQKLLGIPVIVQLSEAEK 194

RNA recognition motif (RRM) found in eukaryotic translation initiation factor 4B (eIF-4B) and similar proteins; This subfamily corresponds to the RRM of eIF-4B, a multi-domain RNA-binding protein that has been primarily implicated in promoting the binding of 40S ribosomal subunits to mRNA during translation initiation. It contains two RNA-binding domains; the N-terminal well-conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), binds the 18S rRNA of the 40S ribosomal subunit and the C-terminal basic domain (BD), including two arginine-rich motifs (ARMs), binds mRNA during initiation, and is primarily responsible for the stimulation of the helicase activity of eIF-4A. eIF-4B also contains a DRYG domain (a region rich in Asp, Arg, Tyr, and Gly amino acids) in the middle, which is responsible for both, self-association of eIF-4B and binding to the p170 subunit of eIF3. Additional research indicates that eIF-4B can interact with the poly(A) binding protein (PABP) in mammalian cells, which can stimulate both, the eIF-4B-mediated activation of the helicase activity of eIF-4A and binding of poly(A) by PABP. eIF-4B has also been shown to interact specifically with the internal ribosome entry sites (IRES) of several picornaviruses which facilitate cap-independent translation initiation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740  40 PPYTAYVGNLPFNTVQGDIDAIFKDLSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRVDIAEGR 119
Cdd:cd12402    1 PPYTAYLGNLPYDVTEDDIEDFFRGLNISSVRLPRENGPGRLRGFGYVEFEDRESLIQALSLNEESLKNRRIRVDVAGQA 80

                 .
gi 929653740 120 K 120
Cdd:cd12402   81 Q 81

RNA recognition motif 1 (RRM1) found in nucleolin-like proteins mainly from plants; This subfamily corresponds to the RRM1 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 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRVDIAEGR 119
Cdd:cd12450    1 TLFVGNLSWSATQDDLENFFSDCgEVVDVRIAMDRDDGRSKGFGHVEFASAESAQKALEKSGQDLGGREIRLDLANER 78

RNA recognition motif 2 (RRM2) found in RNA-binding protein 34 (RBM34) and similar proteins; This subfamily corresponds to the RRM2 of RBM34, a putative RNA-binding protein containing two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). Although the function of RBM34 remains unclear currently, its RRM domains may participate in mRNA processing. RBM34 may act as an mRNA processing-related protein.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKD-LSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12395    1 SVFVGNLPFDIEEEELRKHFEDcGDVEAVRIVRDRETGIGKGFGYVLFKDKDSVDLALKLNGSKLRGRKLRV 72

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 929653740    43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRV 113
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFgKVESVRLVRDKETGKSKGFAFVEFESEEDAEKALEaLNGKELDGRPLKV 73

RNA recognition motif (RRM) found in ist3 family; This subfamily corresponds to the RRM of the ist3 family that includes fungal U2 small nuclear ribonucleoprotein (snRNP) component increased sodium tolerance protein 3 (ist3), X-linked 2 RNA-binding motif proteins (RBMX2) found in Metazoa and plants, and similar proteins. Gene IST3 encoding ist3, also termed U2 snRNP protein SNU17 (Snu17p), is a novel yeast Saccharomyces cerevisiae protein required for the first catalytic step of splicing and for progression of spliceosome assembly. It binds specifically to the U2 snRNP and is an intrinsic component of prespliceosomes and spliceosomes. Yeast ist3 contains an atypical RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). In the yeast pre-mRNA retention and splicing complex, the atypical RRM of ist3 functions as a scaffold that organizes the other two constituents, Bud13p (bud site selection 13) and Pml1p (pre-mRNA leakage 1). Fission yeast Schizosaccharomyces pombe gene cwf29 encoding ist3, also termed cell cycle control protein cwf29, is an RNA-binding protein complexed with cdc5 protein 29. It also contains one RRM. The biological function of RBMX2 remains unclear. It shows high sequence similarity to yeast ist3 protein and harbors one RRM as well.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDE-------VDSLkealtyDGALLGDRSLRVD 114
Cdd:cd12411   13 YIGGLPYELTEGDILCVFSQYgEIVDINLVRDKKTGKSKGFAFLAYEDqrstilaVDNL------NGIKLLGRTIRVD 84

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 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12306    3 YVGNVDYGTTPEELQAHFKSCgTINRVTILCDKFTGQPKGFAYIEFVDKSSVENALLLNESEFRGRQIKV 72

RNA recognition motif (RRM) found in cleavage stimulation factor subunit 2 (CSTF2), yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins; This subfamily corresponds to the RRM domain of CSTF2, its tau variant and eukaryotic homologs. CSTF2, also termed cleavage stimulation factor 64 kDa subunit (CstF64), is the vertebrate conterpart of yeast mRNA 3'-end-processing protein RNA15. It is expressed in all somatic tissues and is one of three cleavage stimulatory factor (CstF) subunits required for polyadenylation. CstF64 contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a CstF77-binding domain, a repeated MEARA helical region and a conserved C-terminal domain reported to bind the transcription factor PC-4. During polyadenylation, CstF interacts with the pre-mRNA through the RRM of CstF64 at U- or GU-rich sequences within 10 to 30 nucleotides downstream of the cleavage site. CSTF2T, also termed tauCstF64, is a paralog of the X-linked cleavage stimulation factor CstF64 protein that supports polyadenylation in most somatic cells. It is expressed during meiosis and subsequent haploid differentiation in a more limited set of tissues and cell types, largely in meiotic and postmeiotic male germ cells, and to a lesser extent in brain. The loss of CSTF2T will cause male infertility, as it is necessary for spermatogenesis and fertilization. Moreover, CSTF2T is required for expression of genes involved in morphological differentiation of spermatids, as well as for genes having products that function during interaction of motile spermatozoa with eggs. It promotes germ cell-specific patterns of polyadenylation by using its RRM to bind to different sequence elements downstream of polyadenylation sites than does CstF64. The family also includes yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins. RNA15 is a core subunit of cleavage factor IA (CFIA), an essential transcriptional 3'-end processing factor from Saccharomyces cerevisiae. RNA recognition by CFIA is mediated by an N-terminal RRM, which is contained in the RNA15 subunit of the complex. The RRM of RNA15 has a strong preference for GU-rich RNAs, mediated by a binding pocket that is entirely conserved in both yeast and vertebrate RNA15 orthologs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 929653740  42 YTAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRVDIA 116
Cdd:cd12398    1 RSVFVGNIPYDATEEQLKEIFSEVgPVVSFRLVTDRETGKPKGYGFCEFRDAETALSAVrNLNGYELNGRPLRVDFA 77

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVDIA 116
Cdd:cd21608    3 YVGNLSWDTTEDDLRDLFSEFgEVESAKVITDRETGRSRGFGFVTFSTAEAAEAAIDaLNGKELDGRSIVVNEA 76

RNA recognition motif 1 (RRM1) found in Arabidopsis thaliana phragmoplastin interacting protein 1 (PHIP1) and similar proteins; This subfamily corresponds to the RRM1 of PHIP1. A. thaliana PHIP1 and its homologs represent a novel class of plant-specific RNA-binding proteins that may play a unique role in the polarized mRNA transport to the vicinity of the cell plate. The family members consist of multiple functional domains, including a lysine-rich domain (KRD domain) that contains three nuclear localization motifs (KKKR/NK), two RNA recognition motifs (RRMs), and three CCHC-type zinc fingers. PHIP1 is a peripheral membrane protein and is localized at the cell plate during cytokinesis in plants. In addition to phragmoplastin, PHIP1 interacts with two Arabidopsis small GTP-binding proteins, Rop1 and Ran2. However, PHIP1 interacted only with the GTP-bound form of Rop1 but not the GDP-bound form. It also binds specifically to Ran2 mRNA.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 929653740  44 AYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12271    1 VYVGGIPYYSTEAEIRSYFSSCgEVRSVDLMRFPDSGNFRGIAFITFKTEEAAKRALALDGEMLGNRFLKV 71

RNA recognition motif (RRM) found in U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) and similar proteins; This subfamily corresponds to the RRM of U1-70K, also termed snRNP70, a key component of the U1 snRNP complex, which is one of the key factors facilitating the splicing of pre-mRNA via interaction at the 5' splice site, and is involved in regulation of polyadenylation of some viral and cellular genes, enhancing or inhibiting efficient poly(A) site usage. U1-70K plays an essential role in targeting the U1 snRNP to the 5' splice site through protein-protein interactions with regulatory RNA-binding splicing factors, such as the RS protein ASF/SF2. Moreover, U1-70K protein can specifically bind to stem-loop I of the U1 small nuclear RNA (U1 snRNA) contained in the U1 snRNP complex. It also mediates the binding of U1C, another U1-specific protein, to the U1 snRNP complex. U1-70K contains a conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by an adjacent glycine-rich region at the N-terminal half, and two serine/arginine-rich (SR) domains at the C-terminal half. The RRM is responsible for the binding of stem-loop I of U1 snRNA molecule. Additionally, the most prominent immunodominant region that can be recognized by auto-antibodies from autoimmune patients may be located within the RRM. The SR domains are involved in protein-protein interaction with SR proteins that mediate 5' splice site recognition. For instance, the first SR domain is necessary and sufficient for ASF/SF2 Binding. The family also includes Drosophila U1-70K that is an essential splicing factor required for viability in flies, but its SR domain is dispensable. The yeast U1-70k doesn't contain easily recognizable SR domains and shows low sequence similarity in the RRM region with other U1-70k proteins and therefore not included in this family. The RRM domain is dispensable for yeast U1-70K function.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTY-DGALLGDRSLRVDIAEGR 119
Cdd:cd12236    3 TLFVARLSYDTTESKLRREFEKYgPIKRVRLVRDKKTGKSRGYAFIEFEHERDMKAAYKHaDGKKIDGRRVLVDVERGR 81

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDLS-IRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVDIA 116
Cdd:cd12413    1 TLFVRNLPYDTTDEQLEELFSDVGpVKRCFVVKDKGKDKCRGFGYVTFALAEDAQRALEeVKGKKFGGRKIKVELA 76

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVDIAEGR 119
Cdd:cd12284    2 YVGSLHFNITEDMLRGIFEPFgKIEFVQLQKDPETGRSKGYGFIQFRDAEDAKKALEqLNGFELAGRPMKVGHVTER 78

RNA recognition motif (RRM) found in Saccharomyces cerevisiae U1 small nuclear ribonucleoprotein SNP1 and similar proteins; SNP1, also called U1 snRNP protein SNP1, or U1 small nuclear ribonucleoprotein 70 kDa homolog, or U1 70K, or U1 snRNP 70 kDa homolog, interacts with mRNA and is involved in nuclear mRNA splicing. It is a component of the spliceosome, where it is associated with snRNP U1 by binding stem loop I of U1 snRNA. Members in this family contain an N-terminal U1snRNP70 domain and an RNA recognition motif (RRM), also called RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740  41 PY-TAYVGNLPFNTVQGDIDAIF-KDLSIRSVRLVRDKDTDKFKGFCYVEF-DEVDS---LKEALTYDGALLGDRSLRVD 114
Cdd:cd21615   17 PYkTLFVGRLDYSLTELELQKKFsKFGEIEKIRIVRDKETGKSRGYAFIVFkSESDAknaFKEGNGLRGLKINDRTCIVD 96

                 ....*
gi 929653740 115 IAEGR 119
Cdd:cd21615   97 IERGR 101

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        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRVDIAEGRK 120
Cdd:cd21609    3 YVGNIPRNVTSEELAKIFEEAgTVEIAEVMYDRYTGRSRGFGFVTMGSVEDAKAAIeKLNGTEVGGREIKVNITEKPL 80

RNA recognition motif (RRM) found in cold inducible RNA binding protein (CIRBP), RNA binding motif protein 3 (RBM3) and similar proteins; This subfamily corresponds to the RRM domain of two structurally related heterogenous nuclear ribonucleoproteins, CIRBP (also termed CIRP or A18 hnRNP) and RBM3 (also termed RNPL), both of which belong to a highly conserved cold shock proteins family. The cold shock proteins can be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. CIRBP and RBM3 may function in posttranscriptional regulation of gene expression by binding to different transcripts, thus allowing the cell to response rapidly to environmental signals. However, the kinetics and degree of cold induction are different between CIRBP and RBM3. Tissue distribution of their expression is different. CIRBP and RBM3 may be differentially regulated under physiological and stress conditions and may play distinct roles in cold responses of cells. CIRBP, also termed glycine-rich RNA-binding protein CIRP, is localized in the nucleus and mediates the cold-induced suppression of cell cycle progression. CIRBP also binds DNA and possibly serves as a chaperone that assists in the folding/unfolding, assembly/disassembly and transport of various proteins. RBM3 may enhance global protein synthesis and the formation of active polysomes while reducing the levels of ribonucleoprotein complexes containing microRNAs. RBM3 may also serve to prevent the loss of muscle mass by its ability to decrease cell death. Furthermore, RBM3 may be essential for cell proliferation and mitosis. Both, CIRBP and RBM3, contain an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), that is involved in RNA binding, and C-terminal glycine-rich domain (RGG motif) that probably enhances RNA-binding via protein-protein and/or protein-RNA interactions. Like CIRBP, RBM3 can also bind to both RNA and DNA via its RRM domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVDIAE 117
Cdd:cd12449    4 FVGGLSFDTNEQSLEEVFSKYgQISEVVVVKDRETQRSRGFGFVTFENPDDAKDAMMaMNGKSLDGRQIRVDQAG 78

RNA recognition motif 1 (RRM1) found in yeast protein gar2 and similar proteins; This subfamily corresponds to the RRM1 of yeast protein gar2, a novel nucleolar protein required for 18S rRNA and 40S ribosomal subunit accumulation. It shares similar domain architecture with nucleolin from vertebrates and NSR1 from Saccharomyces cerevisiae. The highly phosphorylated N-terminal domain of gar2 is made up of highly acidic regions separated from each other by basic sequences, and contains multiple phosphorylation sites. The central domain of gar2 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RGG (or GAR) domain of gar2 is rich in glycine, arginine and phenylalanine residues.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTY-DGALLGDRSLRVDIA 116
Cdd:cd12447    1 TLFVGGLSWNVDDPWLKKEFEKYgGVISARVITDRGSGRSKGYGYVDFATPEAAQKALAAmSGKEIDGRQINVDFS 76

RNA recognition motif (RRM) found in heterogeneous nuclear ribonucleoprotein (hnRNP) H protein family, epithelial splicing regulatory proteins (ESRPs), Drosophila RNA-binding protein Fusilli, RNA-binding protein 12 (RBM12) and similar proteins; The family includes RRM domains in the hnRNP H protein family, G-rich sequence factor 1 (GRSF-1), ESRPs (also termed RBM35), Drosophila Fusilli, RBM12 (also termed SWAN), RBM12B, RBM19 (also termed RBD-1) and similar proteins. The hnRNP H protein family includes hnRNP H (also termed mcs94-1), hnRNP H2 (also termed FTP-3 or hnRNP H'), hnRNP F and hnRNP H3 (also termed hnRNP 2H9), which represent a group of nuclear RNA binding proteins that are involved in pre-mRNA processing. GRSF-1 is a cytoplasmic poly(A)+ mRNA binding protein which interacts with RNA in a G-rich element-dependent manner. It may function in RNA packaging, stabilization of RNA secondary structure, or other macromolecular interactions. ESRP1 (also termed RBM35A) and ESRP2 (also termed RBM35B) are epithelial-specific RNA binding proteins that promote splicing of the epithelial variant of fibroblast growth factor receptor 2 (FGFR2), ENAH (also termed hMena), CD44 and CTNND1 (also termed p120-Catenin) transcripts. Fusilli shows high sequence homology to ESRPs. It can regulate endogenous FGFR2 splicing and functions as a splicing factor. The biological roles of both, RBM12 and RBM12B, remain unclear. RBM19 is a nucleolar protein conserved in eukaryotes. It is involved in ribosome biogenesis by processing rRNA. In addition, it is essential for preimplantation development. Members in this family contain 2~6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 929653740  48 NLPFNTVQGDIDAIFKDLSIR--SVRLVRDKDtDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12254    6 GLPFSATEEDIRDFFSGLDIPpdGIHIVYDDD-GRPTGEAYVEFASEEDAQRALRRHKGKMGGRYIEV 72

RNA recognition motif in type II polyadenylate-binding protein 2 (PABP-2) and similar proteins; This subgroup corresponds to the RRM of PABP-2, also termed poly(A)-binding protein 2, or nuclear poly(A)-binding protein 1 (PABPN1), or poly(A)-binding protein II (PABII), which is a ubiquitously expressed type II nuclear poly(A)-binding protein that directs the elongation of mRNA poly(A) tails during pre-mRNA processing. Although PABP-2 binds poly(A) with high affinity and specificity as type I poly(A)-binding proteins, it contains only one highly conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is responsible for the poly(A) binding. In addition, PABP-2 possesses an acidic N-terminal domain that is essential for the stimulation of PAP, and an arginine-rich C-terminal domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12550    3 YVGNVDYGATAEELEAHFHGCgSVNRVTILCDKFSGHPKGFAYIEFADKESVRTALALDESLFRGRQIKV 72

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 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFK---GFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12298    4 RVRNLDFELDEEALRGIFEKFgEIESINIPKKQKNRKGRhnnGFAFVTFEDADSAESALQLNGTLLDNRKISV 76

RNA recognition motif 1 (RRM1) and 2 (RRM2) found in RNA-binding protein 5 (RBM5) and similar proteins; This subfamily includes the RRM1 and RRM2 of RNA-binding protein 5 (RBM5 or LUCA15 or H37) and RNA-binding protein 10 (RBM10 or S1-1), and the RRM2 of RNA-binding protein 6 (RBM6 or NY-LU-12 or g16 or DEF-3). These RBMs share high sequence homology and may play an important role in regulating apoptosis. RBM5 is a known modulator of apoptosis. It may also act as a tumor suppressor or an RNA splicing factor. RBM6 has been predicted to be a nuclear factor based on its nuclear localization signal. Both, RBM6 and RBM5, specifically bind poly(G) RNA. RBM10 is a paralog of RBM5. It may play an important role in mRNA generation, processing and degradation in several cell types. The rat homolog of human RBM10 is protein S1-1, a hypothetical RNA binding protein with poly(G) and poly(U) binding capabilities. All family members contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), two C2H2-type zinc fingers, and a G-patch/D111 domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 929653740  53 TVQGDIDAIFK---DLSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL 99
Cdd:cd12313   14 TTEEDILSALQahaDLPIKDVRLIRDKLTGTSRGFAFVEFSSLEDATQVM 63

RNA recognition motif 1 and 2 (RRM1, RRM2) found in Arabidopsis thaliana CTC-interacting domain protein CID8, CID9, CID10, CID11, CID12, CID 13 and similar proteins; This subgroup corresponds to the RRM domains found in A. thaliana CID8, CID9, CID10, CID11, CID12, CID 13 and mainly their plant homologs. These highly related RNA-binding proteins contain an N-terminal PAM2 domain (PABP-interacting motif 2), two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a basic region that resembles a bipartite nuclear localization signal. The biological role of this family remains unclear.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFK-DLSIRSVRLVRDKDTDKFkgfCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12225    2 TIHVGGIDGSLSEDELADYFSnCGEVTQVRLCGDRVHTRF---AWVEFATDASALSALNLDGTTLGGHPLRV 70

RNA recognition motif 1 (RRM1) found in RNA-binding protein 34 (RBM34) and similar proteins; This subfamily corresponds to the RRM1 of RBM34, a putative RNA-binding protein containing two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). Although the function of RBM34 remains unclear currently, its RRM domains may participate in mRNA processing. RBM34 may act as an mRNA processing-related protein.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRL----------------VRDKDTDKFKGF-CYVEFDEVDSLKEALTYDGA 104
Cdd:cd12394    2 TVFVGNLPVTVKKKALKKLFKEFgKIESVRFrsvavanpklpkkvavIKKKFHPKRDSMnAYVVFKEEESAQKALKLNGT 81

                         90
                 ....*....|
gi 929653740 105 LLGDRSLRVD 114
Cdd:cd12394   82 EFEGHHIRVD 91

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 929653740  45 YVGNLPFNTVQGDIDAIFKDLS-IRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRV 113
Cdd:cd12370    4 YVGSIYFELGEDTIRQAFAPFGpIKSIDMSWDPVTMKHKGFAFVEYEVPEAAQLALeQMNGVMLGGRNIKV 74

RNA recognition motif 1 (RRM1) found in yeast nucleolar protein 4 (Nop4p) and similar proteins; This subgroup corresponds to the RRM1 of Nop4p (also known as Nop77p), encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDLS-IRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRVDIAEGR 119
Cdd:cd12674    2 TLFVRNLPFDVTLESLTDFFSDIGpVKHAVVVTDPETKKSRGYGFVSFSTHDDAEEALAkLKNRKLSGHILKLDFAKPR 80

RNA recognition motif 1 (RRM1) found in Schizosaccharomyces pombe mRNA export factor Crp79 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. 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        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRD--KDTDKFKGFCYVEFDEVDSLKEALT-YDGALLGDRSLRV 113
Cdd:cd21619    3 TIYVGNIDMTINEDALEKIFSRYgQVESVRRPPIhtDKADRTTGFGFIKYTDAESAERAMQqADGILLGRRRLVV 77

RNA recognition motif (RRM) found in Zinc finger CCHC-type and RNA-binding motif-containing protein 1 (ZCRB1) and similar proteins; This subfamily corresponds to the RRM of ZCRB1, also termed MADP-1, or U11/U12 small nuclear ribonucleoprotein 31 kDa protein (U11/U12 snRNP 31 or U11/U12-31K), a novel multi-functional nuclear factor, which may be involved in morphine dependence, cold/heat stress, and hepatocarcinoma. It is located in the nucleoplasm, but outside the nucleolus. ZCRB1 is one of the components of U11/U12 snRNPs that bind to U12-type pre-mRNAs and form a di-snRNP complex, simultaneously recognizing the 5' splice site and branchpoint sequence. ZCRB1 is characterized by an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a CCHC-type Zinc finger motif. In addition, it contains core nucleocapsid motifs, and Lys- and Glu-rich domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 929653740  43 TAYVGNLPFNTVQGDIDAIF-KDLSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRV 113
Cdd:cd12393    3 TVYVSNLPFSLTNNDLHQIFsKYGKVVKVTILKDKETRKSKGVAFVLFLDRESAHNAVrAMNNKELFGRTLKC 75

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 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFK---GFCYVEFDEVDSLKEAL 99
Cdd:cd12318    2 TLFVKNLNFKTTEEALKKHFEKCgPIRSVTIAKKKDPKGPLlsmGYGFVEFKSPEAAQKAL 62

RNA recognition motif in vertebrate type II embryonic polyadenylate-binding protein 2 (ePABP-2); This subgroup corresponds to the RRM of ePABP-2, also termed embryonic poly(A)-binding protein 2, or poly(A)-binding protein nuclear-like 1 (PABPN1L). ePABP-2 is a novel embryonic-specific cytoplasmic type II poly(A)-binding protein that is expressed during the early stages of vertebrate development and in adult ovarian tissue. It may play an important role in the poly(A) metabolism of stored mRNAs during early vertebrate development. ePABP-2 shows significant sequence similarity to the ubiquitously expressed nuclear polyadenylate-binding protein 2 (PABP-2 or PABPN1). Like PABP-2, ePABP-2 contains one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is responsible for the poly(A) binding. In addition, it possesses an acidic N-terminal domain predicted to form a coiled-coil and an arginine-rich C-terminal domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12551    1 SVYVGNVDYGSTADELEAHFNGCgPINRVTILCDKFSGHPKGYAYIEFATRSSVQAAVALDESSFRGRVIKV 72

RNA recognition motif in nucleolar protein interacting with the FHA domain of pKI-67 (NIFK) and similar proteins; This subgroup corresponds to the RRM of NIFK and Nop15p. NIFK, also termed MKI67 FHA domain-interacting nucleolar phosphoprotein, or nucleolar phosphoprotein Nopp34, is a putative RNA-binding protein interacting with the forkhead associated (FHA) domain of pKi-67 antigen in a mitosis-specific and phosphorylation-dependent manner. It is nucleolar in interphase but associates with condensed mitotic chromosomes. This family also includes Saccharomyces cerevisiae YNL110C gene encoding ribosome biogenesis protein 15 (Nop15p), also termed nucleolar protein 15. Both, NIFK and Nop15p, contain an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 929653740  45 YVGNLPFNTVQGDIDAIFKDL-SIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKE-ALTYDGALLGDRSLRV 113
Cdd:cd12307    3 YIGHLPHGFYEPELRKYFSQFgTVTRLRLSRSKKTGKSKGYAFVEFEDPEVAKIvAETMNNYLLFERLLKC 73

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDLSirSVRLVRDKDTdKFKGFCYVEFDEVDSLKEAL-TYDGALLGDRSLRVD 114
Cdd:cd12404    5 TLFVKNLPYSTTQDELKEVFEDAV--DIRIPMGRDG-RSKGIAYIEFKSEAEAEKALeEKQGTEVDGRSIVVD 74

RNA recognition motif (RRM) found in transformer-2 protein homolog TRA2-alpha, TRA2-beta and similar proteins; This subfamily corresponds to the RRM of two mammalian homologs of Drosophila transformer-2 (Tra2), TRA2-alpha, TRA2-beta (also termed SFRS10), and similar proteins found in eukaryotes. TRA2-alpha is a 40-kDa serine/arginine-rich (SR) protein that specifically binds to gonadotropin-releasing hormone (GnRH) exonic splicing enhancer on exon 4 (ESE4) and is necessary for enhanced GnRH pre-mRNA splicing. It strongly stimulates GnRH intron A excision in a dose-dependent manner. In addition, TRA2-alpha can interact with either 9G8 or SRp30c, which may also be crucial for ESE-dependent GnRH pre-mRNA splicing. TRA2-beta is a serine/arginine-rich (SR) protein that controls the pre-mRNA alternative splicing of the calcitonin/calcitonin gene-related peptide (CGRP), the survival motor neuron 1 (SMN1) protein and the tau protein. Both, TRA2-alpha and TRA2-beta, contains a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), flanked by the N- and C-terminal arginine/serine (RS)-rich regions.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 929653740  46 VGNLPFNTVQGDIDAIFKD-LSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEA-LTYDGALLGDRSLRVDIA 116
Cdd:cd12363    6 VFGLSLYTTERDLREVFSRyGPIEKVQVVYDQQTGRSRGFGFVYFESVEDAKEAkERLNGQEIDGRRIRVDYS 78

RNA recognition motif 2 (RRM2) found in Arabidopsis thaliana CTC-interacting domain protein CID8, CID9, CID10, CID11, CID12, CID 13 and similar proteins; This subgroup corresponds to the RRM2 domains found in A. thaliana CID8, CID9, CID10, CID11, CID12, CID 13 and mainly their plant homologs. These highly related RNA-binding proteins contain an N-terminal PAM2 domain (PABP-interacting motif 2), two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a basic region that resembles a bipartite nuclear localization signal. The biological role of this family remains unclear.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 929653740  43 TAYVGNLPFNTVQGDIDAIFKDLSIRSVRLVRDKDTDKFKGFCYVEFDEVDSLKEALTYDGALLGDRSLRV 113
Cdd:cd12460    6 TIYCTNIDKKVTQDDVKAFFESLCGEVHRLRLLGDYVHSTRIAFVEFVMAESAIAALNCSGALLGSLPIRV 76