RNA recognition motif (RRM) found in the cell surface Ecto-NOX disulfide-thiol exchanger (ECTO-NOX or ENOX) proteins; This subgroup corresponds to the conserved RNA recognition motif (RRM) in ECTO-NOX proteins (also termed ENOX), comprising a family of plant and animal NAD(P)H oxidases exhibiting both, oxidative and protein disulfide isomerase-like, activities. They are growth-related and drive cell enlargement, and may play roles in aging and neurodegenerative diseases. ENOX proteins function as terminal oxidases of plasma membrane electron transport (PMET) through catalyzing electron transport from plasma membrane quinones to extracellular oxygen, forming water as a product. They are also hydroquinone oxidases that oxidize externally supplied NADH, hence NOX. ENOX proteins harbor a di-copper center that lack flavin. ENOX proteins display protein disulfide interchange activity that is also possessed by protein disulfide isomerase. In contrast to the classic protein disulfide isomerases, ENOX proteins lack the double CXXC motif. This family includes two ENOX proteins, ENOX1 and ENOX2. ENOX1, also termed candidate growth-related and time keeping constitutive hydroquinone [NADH] oxidase (cCNOX), or cell proliferation-inducing gene 38 protein, or Constitutive Ecto-NOX (cNOX), is the constitutively expressed cell surface NADH (ubiquinone) oxidase that is ubiquitous and refractory to drugs. ENOX2, also termed APK1 antigen, or cytosolic ovarian carcinoma antigen 1, or tumor-associated hydroquinone oxidase (tNOX), is a cancer-specific variant of ENOX1 and plays a key role in cell proliferation and tumor progression. In contrast to ENOX1, ENOX2 is drug-responsive and harbors a drug binding site to which the cancer-specific S-peptide tagged pan-ENOX2 recombinant (scFv) is directed. Moreover, ENOX2 is specifically inhibited by a variety of quinone site inhibitors that have anticancer activity and is unique to the surface of cancer cells. ENOX proteins contain many functional motifs.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 136 ERPPGCKTVFVGGLPENATEEIIQEVFEQCGDITAIRKSKKNFCHIRFAEEFMVDKAIYLSGYRMRLGSSTDKKDSGRLH 215
Cdd:cd12228    1 ERPPGCKTVFVGGLPENATEEIIREVFEQCGEIIAIRMSKKNFCHIRFAEEFAVDKAIYLSGYRVRLGSSTDPKNTGRLH 80

                 ....
gi 568987654 216 VDFA 219
Cdd:cd12228   81 VDFA 84

RNA recognition motif (RRM) found in the cell surface Ecto-NOX disulfide-thiol exchanger (ECTO-NOX or ENOX) proteins; This subgroup corresponds to the conserved RNA recognition motif (RRM) in ECTO-NOX proteins (also termed ENOX), comprising a family of plant and animal NAD(P)H oxidases exhibiting both, oxidative and protein disulfide isomerase-like, activities. They are growth-related and drive cell enlargement, and may play roles in aging and neurodegenerative diseases. ENOX proteins function as terminal oxidases of plasma membrane electron transport (PMET) through catalyzing electron transport from plasma membrane quinones to extracellular oxygen, forming water as a product. They are also hydroquinone oxidases that oxidize externally supplied NADH, hence NOX. ENOX proteins harbor a di-copper center that lack flavin. ENOX proteins display protein disulfide interchange activity that is also possessed by protein disulfide isomerase. In contrast to the classic protein disulfide isomerases, ENOX proteins lack the double CXXC motif. This family includes two ENOX proteins, ENOX1 and ENOX2. ENOX1, also termed candidate growth-related and time keeping constitutive hydroquinone [NADH] oxidase (cCNOX), or cell proliferation-inducing gene 38 protein, or Constitutive Ecto-NOX (cNOX), is the constitutively expressed cell surface NADH (ubiquinone) oxidase that is ubiquitous and refractory to drugs. ENOX2, also termed APK1 antigen, or cytosolic ovarian carcinoma antigen 1, or tumor-associated hydroquinone oxidase (tNOX), is a cancer-specific variant of ENOX1 and plays a key role in cell proliferation and tumor progression. In contrast to ENOX1, ENOX2 is drug-responsive and harbors a drug binding site to which the cancer-specific S-peptide tagged pan-ENOX2 recombinant (scFv) is directed. Moreover, ENOX2 is specifically inhibited by a variety of quinone site inhibitors that have anticancer activity and is unique to the surface of cancer cells. ENOX proteins contain many functional motifs.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 136 ERPPGCKTVFVGGLPENATEEIIQEVFEQCGDITAIRKSKKNFCHIRFAEEFMVDKAIYLSGYRMRLGSSTDKKDSGRLH 215
Cdd:cd12228    1 ERPPGCKTVFVGGLPENATEEIIREVFEQCGEIIAIRMSKKNFCHIRFAEEFAVDKAIYLSGYRVRLGSSTDPKNTGRLH 80

                 ....
gi 568987654 216 VDFA 219
Cdd:cd12228   81 VDFA 84

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
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 568987654  144 VFVGGLPENATEEIIQEVFEQCGDITAIR------KSKKNFCHIRFAEEFMVDKAI 193
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRlvrdetGRSKGFAFVEFEDEEDAEKAI 56

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

                         10        20        30
                 ....*....|....*....|....*....|.
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIR 172
Cdd:COG0724    2 MKIYVGNLPYSVTEEDLRELFSEYGEVTSVK 32

RNA recognition motif (RRM) found in the cell surface Ecto-NOX disulfide-thiol exchanger (ECTO-NOX or ENOX) proteins; This subgroup corresponds to the conserved RNA recognition motif (RRM) in ECTO-NOX proteins (also termed ENOX), comprising a family of plant and animal NAD(P)H oxidases exhibiting both, oxidative and protein disulfide isomerase-like, activities. They are growth-related and drive cell enlargement, and may play roles in aging and neurodegenerative diseases. ENOX proteins function as terminal oxidases of plasma membrane electron transport (PMET) through catalyzing electron transport from plasma membrane quinones to extracellular oxygen, forming water as a product. They are also hydroquinone oxidases that oxidize externally supplied NADH, hence NOX. ENOX proteins harbor a di-copper center that lack flavin. ENOX proteins display protein disulfide interchange activity that is also possessed by protein disulfide isomerase. In contrast to the classic protein disulfide isomerases, ENOX proteins lack the double CXXC motif. This family includes two ENOX proteins, ENOX1 and ENOX2. ENOX1, also termed candidate growth-related and time keeping constitutive hydroquinone [NADH] oxidase (cCNOX), or cell proliferation-inducing gene 38 protein, or Constitutive Ecto-NOX (cNOX), is the constitutively expressed cell surface NADH (ubiquinone) oxidase that is ubiquitous and refractory to drugs. ENOX2, also termed APK1 antigen, or cytosolic ovarian carcinoma antigen 1, or tumor-associated hydroquinone oxidase (tNOX), is a cancer-specific variant of ENOX1 and plays a key role in cell proliferation and tumor progression. In contrast to ENOX1, ENOX2 is drug-responsive and harbors a drug binding site to which the cancer-specific S-peptide tagged pan-ENOX2 recombinant (scFv) is directed. Moreover, ENOX2 is specifically inhibited by a variety of quinone site inhibitors that have anticancer activity and is unique to the surface of cancer cells. ENOX proteins contain many functional motifs.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 136 ERPPGCKTVFVGGLPENATEEIIQEVFEQCGDITAIRKSKKNFCHIRFAEEFMVDKAIYLSGYRMRLGSSTDKKDSGRLH 215
Cdd:cd12228    1 ERPPGCKTVFVGGLPENATEEIIREVFEQCGEIIAIRMSKKNFCHIRFAEEFAVDKAIYLSGYRVRLGSSTDPKNTGRLH 80

                 ....
gi 568987654 216 VDFA 219
Cdd:cd12228   81 VDFA 84

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
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDITAIR------KSKKNFCHIRFAEEFMVDKAI 193
Cdd:cd00590    1 LFVGNLPPDTTEEDLRELFSKFGEVVSVRivrdrdGKSKGFAFVEFESPEDAEKAL 56

RNA recognition motif 2 (RRM2) found in Arabidopsis thaliana phragmoplastin interacting protein 1 (PHIP1) and similar proteins; The CD corresponds to the RRM2 of PHIP1. A. thaliana PHIP1 and its homologs represent a novel class of plant-specific RNA-binding proteins that may play a unique role in the polarized mRNA transport to the vicinity of the cell plate. The family members consist of multiple functional domains, including a lysine-rich domain (KRD domain) that contains three nuclear localization motifs (KKKR/NK), two RNA recognition motifs (RRMs), and three CCHC-type zinc fingers. PHIP1 is a peripheral membrane protein and is localized at the cell plate during cytokinesis in plants. In addition to phragmoplastin, PHIP1 interacts with two Arabidopsis small GTP-binding proteins, Rop1 and Ran2. However, PHIP1 interacted only with the GTP-bound form of Rop1 but not the GDP-bound form. It also binds specifically to Ran2 mRNA.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 568987654 143 TVFVGGLPENATEEIIQEVFEQCGDITAIRKSK-------KNFCHIRFAEEFMVDKAIYLSG 197
Cdd:cd12272    1 TVYIGNLAWDIDEDDLRELFAECCEITNVRLHTdketgefKGYGHVEFADEESLDAALKLAG 62

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
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 568987654  144 VFVGGLPENATEEIIQEVFEQCGDITAIR------KSKKNFCHIRFAEEFMVDKAI 193
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRlvrdetGRSKGFAFVEFEDEEDAEKAI 56

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDI--TAIRKSK-----KNFCHIRFAEEFMVDKAIYLSG 197
Cdd:cd12306    2 IYVGNVDYGTTPEELQAHFKSCGTInrVTILCDKftgqpKGFAYIEFVDKSSVENALLLNE 62

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 568987654 143 TVFVGGLPENATEEIIQEVFEQCGDITAIRKSK-KNFCHIRFA 184
Cdd:cd12354    2 TVYVGNITKGLTEALLQQTFSPFGQILEVRVFPdKGYAFIRFD 44

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIRK----SKKNFCHIRFAEEFMVDKAIYLSGyrMRLGSST 206
Cdd:cd12225    1 RTIHVGGIDGSLSEDELADYFSNCGEVTQVRLcgdrVHTRFAWVEFATDASALSALNLDG--TTLGGHP 67

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        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDITAI-----RKS--KKNFCHIRFAEEFMVDKAIyLSGYRMRLGSSTDKK 209
Cdd:cd12328    2 LFVGGLKEDVEEEDLREYFSQFGKVESVeivtdKETgkKRGFAFVTFDDHDSVDKIV-LQKYHTINGHRCEVK 73

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIRKSK------KNFCHIRFAEEFMVDKAIYL 195
Cdd:cd12336    2 RTLFVGNLDPRVTEEILYELFLQAGPLEGVKIPKdpngkpKNFAFVTFKHEVSVPYAIQL 61

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein A/B (hnRNP A/B) and similar proteins; This subgroup corresponds to the RRM2 of hnRNP A/B, also termed APOBEC1-binding protein 1 (ABBP-1), 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 A/B contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long C-terminal glycine-rich domain that contains a potential ATP/GTP binding loop.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIR-------KSKKNFCHIRFAEEFMVDKAI 193
Cdd:cd12584    5 KKIFVGGLNPETTEEKIREYFGEFGEIEAIElpmdpktNKRRGFVFITFKEEDPVKKIL 63

RNA recognition motif 2 (RRM2) found in splicing regulatory glutamine/lysine-rich protein 1 (SREK1) and similar proteins; This subfamily corresponds to the RRM2 of SREK1, also termed serine/arginine-rich-splicing regulatory protein 86-kDa (SRrp86), or splicing factor arginine/serine-rich 12 (SFRS12), or splicing regulatory protein 508 amino acid (SRrp508). SREK1 belongs to a family of proteins containing regions rich in serine-arginine dipeptides (SR proteins family), which is involved in bridge-complex formation and splicing by mediating protein-protein interactions across either introns or exons. It is a unique SR family member and it may play a crucial role in determining tissue specific patterns of alternative splicing. SREK1 can alter splice site selection by both positively and negatively modulating the activity of other SR proteins. For instance, SREK1 can activate SRp20 and repress SC35 in a dose-dependent manner both in vitro and in vivo. In addition, SREK1 contains two (some contain only one) RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and two serine-arginine (SR)-rich domains (SR domains) separated by an unusual glutamic acid-lysine (EK) rich region. The RRM and SR domains are highly conserved among other members of the SR superfamily. However, the EK domain is unique to SREK1. It plays a modulatory role controlling SR domain function by involvement in the inhibition of both constitutive and alternative splicing and in the selection of splice-site.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIR-----KSKKNFCHIRFAEEFMVDKAIYLSG 197
Cdd:cd12260    5 RTVYVGNLDPSTTADQLLEFFSQAGEVKYVRmagdeTQPTRYAFVEFAEQTSVINALKLNG 65

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
                 ....*....|....*....|....*....|.
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIR 172
Cdd:cd12392    3 NKLFVKGLPFSCTKEELEELFKQHGTVKDVR 33

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        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIR--------KSKK-NFCHirFAEEFMVDKAI-YLSGYRMRlgsstdkkds 211
Cdd:cd12398    1 RSVFVGNIPYDATEEQLKEIFSEVGPVVSFRlvtdretgKPKGyGFCE--FRDAETALSAVrNLNGYELN---------- 68

                 ....*....
gi 568987654 212 GR-LHVDFA 219
Cdd:cd12398   69 GRpLRVDFA 77

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDITAIR----KSKKNFC---HIRFAEEFMVDKAIYLSGYRM 200
Cdd:cd12271    1 VYVGGIPYYSTEAEIRSYFSSCGEVRSVDlmrfPDSGNFRgiaFITFKTEEAAKRALALDGEML 64

RNA recognition motif 2 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM2 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568987654 143 TVFVGGLPENATEEIIQEVFEQCGDITAIR------KSKKNFCHIRFAEEFMVDKAIYLSG 197
Cdd:cd12297    2 TLWVTNFPPSYDERSIRDLFGDYGVILSVRlpslryNTSRRFCYIDFTSPESARAAVELLN 62

RNA recognition motif (RRM) found in vertebrate RNA-binding protein 11 (RBM11); This subfamily corresponds to the RRM or RBM11, a novel tissue-specific splicing regulator that is selectively expressed in brain, cerebellum and testis, and to a lower extent in kidney. RBM11 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. RBM11 contains 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 of RBM11 is responsible for RNA binding, whereas the C-terminal region permits nuclear localization and homodimerization.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDITAIRKSK------KNFCHIRFAEEFMVDKAIYL 195
Cdd:cd12593    2 RTVFVGNLHSNVNEEILYELFLQAGPLTKVTIAKdkegkpKSFGFVCFKHAESVPYAIAL 61

RNA recognition motif 2 (RRM2) found in RNA-binding protein MRN1 and similar proteins; This subgroup corresponds to the RRM2 of MRN1, also termed multicopy suppressor of RSC-NHP6 synthetic lethality protein 1, or post-transcriptional regulator of 69 kDa, which is a RNA-binding protein found in yeast. Although its specific biological role remains unclear, MRN1 might be involved in translational regulation. Members in this family contain four copies of conserved RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 568987654 141 CKTVFVGGLPENATEEIIQEVFEQCGDITAIR-KSKKNFCHIRFA 184
Cdd:cd12523    3 SRNVYLGNLPESITEEELREDLEKFGPIDQIKiVKEKNIAFVHFL 47

RNA recognition motif (RRM) found in the FET family of RNA-binding proteins; This subfamily corresponds to the RRM of FET (previously TET) (FUS/TLS, EWS, TAF15) family of RNA-binding proteins. This ubiquitously expressed family of similarly structured proteins predominantly localizing to the nuclear, includes FUS (also known as TLS or Pigpen or hnRNP P2), EWS (also known as EWSR1), TAF15 (also known as hTAFII68 or TAF2N or RPB56), and Drosophila Cabeza (also known as SARFH). The corresponding coding genes of these proteins are involved in deleterious genomic rearrangements with transcription factor genes in a variety of human sarcomas and acute leukemias. All FET proteins interact with each other and are therefore likely to be part of the very same protein complexes, which suggests a general bridging role for FET proteins coupling RNA transcription, processing, transport, and DNA repair. The FET proteins contain multiple copies of a degenerate hexapeptide repeat motif at the N-terminus. The C-terminal region consists of a conserved nuclear import and retention signal (C-NLS), a putative zinc-finger domain, and a conserved RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), which is flanked by 3 arginine-glycine-glycine (RGG) boxes. FUS and EWS might have similar sequence specificity; both bind preferentially to GGUG-containing RNAs. FUS has also been shown to bind strongly to human telomeric RNA and to small low-copy-number RNAs tethered to the promoter of cyclin D1. To date, nothing is known about the RNA binding specificity of TAF15.

                         10        20
                 ....*....|....*....|....*
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDI 168
Cdd:cd12280    1 IFVSGLPPDVTIDELADLFGQIGII 25

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
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 568987654 142 KTVFVGGLPENATEEIIQEVFEQCGDI---TAIRKSKKNFCHIRFAEEFMVDKAI 193
Cdd:cd12404    4 RTLFVKNLPYSTTQDELKEVFEDAVDIripMGRDGRSKGIAYIEFKSEAEAEKAL 58

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 568987654 143 TVFVGGLPENATEEIIQEVFeqcGDITAIRKS----KKN------FCHIRFAEEFMVDKAiylsgyrmrLGSSTDKKDSG 212
Cdd:cd12413    1 TLFVRNLPYDTTDEQLEELF---SDVGPVKRCfvvkDKGkdkcrgFGYVTFALAEDAQRA---------LEEVKGKKFGG 68

                         90
                 ....*....|.
gi 568987654 213 R-LHVDFAQAR 222
Cdd:cd12413   69 RkIKVELAKKK 79

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
                 ....*....|....*....|....*....|....*....|....*..
gi 568987654 126 NPNLPPPSTRERPpgCKTVFVGGLPENATEEIIQEVFEQCGDITAIR 172
Cdd:cd21615    5 NPEEDPHIADGDP--YKTLFVGRLDYSLTELELQKKFSKFGEIEKIR 49

RNA recognition motif (RRM) found in Saccharomyces cerevisiae nucleolar protein 6 (Nop6) and similar proteins; This subfamily corresponds to the RRM of Nop6, also known as Ydl213c, a component of 90S pre-ribosomal particles in yeast S. cerevisiae. It is enriched in the nucleolus and is required for 40S ribosomal subunit biogenesis. Nop6 is a non-essential putative RNA-binding protein with two N-terminal putative nuclear localisation sequences (NLS-1 and NLS-2) and an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). It binds to the pre-rRNA early during transcription and plays an essential role in pre-rRNA processing.

                         10        20
                 ....*....|....*....|....*....
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDITAIR 172
Cdd:cd12400    3 LFVGNLPYDTTAEDLKEHFKKAGEPPSVR 31

RNA recognition motif 3 (RRM3) found in yeast negative growth regulatory protein NGR1 (RBP1), yeast protein NAM8 and similar proteins; This subfamily corresponds to the RRM3 of NGR1 and NAM8. NGR1, also termed RNA-binding protein RBP1, is a putative glucose-repressible protein that binds both RNA and single-stranded DNA (ssDNA) in yeast. It may function in regulating cell growth in early log phase, possibly through its participation in RNA metabolism. NGR1 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a glutamine-rich stretch that may be involved in transcriptional activity. In addition, NGR1 has an asparagine-rich region near the carboxyl terminus which also harbors a methionine-rich region. The family also includes protein NAM8, which 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. Like NGR1, NAM8 contains two RRMs.

                         10        20        30
                 ....*....|....*....|....*....|
gi 568987654 143 TVFVGGLPENATEEIIQEVFEQCGDITAIR 172
Cdd:cd12346    3 TVFVGGLDPNVTEEDLRVLFGPFGEIVYVK 32

Chromosome segregation ATPase Smc [Cell cycle control, cell division, chromosome partitioning];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568987654 449 KEENDSLRWQLDAYRNEVELLKQEKEQL-----FRTEENLTKDQQLQFLQQTMQGMQQQLLAIQEELNNKKSELEQAKEE 523
Cdd:COG1196  273 RLELEELELELEEAQAEEYELLAELARLeqdiaRLEERRRELEERLEELEEELAELEEELEELEEELEELEEELEEAEEE 352

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 568987654 524 QSHTQALLKVLQEQLKGTKDLVETNGHSHEDANE--INVLTVALVNQDRENNTEKRSQGLKSEKEALL 589
Cdd:COG1196  353 LEEAEAELAEAEEALLEAEAELAEAEEELEELAEelLEALRAAAELAAQLEELEEAEEALLERLERLE 420

RNA recognition motif 1 (RRM1) and 2 (RRM2) found in RRM-containing coactivator activator/modulator (CoAA) and similar proteins; This subfamily corresponds to the RRM in CoAA (also known as RBM14 or PSP2) and RNA-binding protein 4 (RBM4). CoAA is a heterogeneous nuclear ribonucleoprotein (hnRNP)-like protein identified as a nuclear receptor coactivator. It mediates transcriptional coactivation and RNA splicing effects in a promoter-preferential manner, and is enhanced by thyroid hormone receptor-binding protein (TRBP). CoAA contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a TRBP-interacting domain. RBM4 is a ubiquitously expressed splicing factor with two isoforms, RBM4A (also known as Lark homolog) and RBM4B (also known as RBM30), which are very similar in structure and sequence. RBM4 may also function as a translational regulator of stress-associated mRNAs as well as play a role in micro-RNA-mediated gene regulation. RBM4 contains two N-terminal RRMs, a CCHC-type zinc finger, and three alanine-rich regions within their C-terminal regions. This family also includes Drosophila RNA-binding protein lark (Dlark), a homolog of human RBM4. It plays an important role in embryonic development and in the circadian regulation of adult eclosion. Dlark shares high sequence similarity with RBM4 at the N-terminal region. However, Dlark has three proline-rich segments instead of three alanine-rich segments within the C-terminal region.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCG-----DITairkskKNFCHIRFAEEFMVDKAI 193
Cdd:cd12343    2 IFVGNLPDAATSEELRALFEKYGkvtecDIV------KNYAFVHMEKEEDAEDAI 50

RNA recognition motif (RRM) found in cyclophilin-33 (Cyp33) and similar proteins; This subfamily corresponds to the RRM of Cyp33, also termed peptidyl-prolyl cis-trans isomerase E (PPIase E), or cyclophilin E, or rotamase E. Cyp33 is a nuclear RNA-binding cyclophilin with an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal PPIase domain. Cyp33 possesses RNA-binding activity and preferentially binds to polyribonucleotide polyA and polyU, but hardly to polyG and polyC. It binds specifically to mRNA, which can stimulate its PPIase activity. Moreover, Cyp33 interacts with the third plant homeodomain (PHD3) zinc finger cassette of the mixed lineage leukemia (MLL) proto-oncoprotein and a poly-A RNA sequence through its RRM domain. It further mediates downregulation of the expression of MLL target genes HOXC8, HOXA9, CDKN1B, and C-MYC, in a proline isomerase-dependent manner. Cyp33 also possesses a PPIase activity that catalyzes cis-trans isomerization of the peptide bond preceding a proline, which has been implicated in the stimulation of folding and conformational changes in folded and unfolded proteins. The PPIase activity can be inhibited by the immunosuppressive drug cyclosporin A.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568987654 144 VFVGGLPENATEEIIQEVFEQCGDITAIR-----KSKKN--FCHIRFAEE 186
Cdd:cd12347    1 LYVGGLAEEVDEKVLHAAFIPFGDIVDIQipldyETEKHrgFAFVEFEEA 50