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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 311771527   1 MKIFVGNVDGaDTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGhELRPGRALVVEMS 71
Cdd:cd12608    1 MKIFVGNVDE-DTSQEELSALFEPYGAVLSCAVMKQFAFVHMRGEAAADRAIRELNG-RELHGRALVVEES 69

RNA recognition motif 1 (RRM1) found in vertebrate RRM-containing coactivator activator/modulator (CoAA); This subgroup corresponds to the RRM1 of CoAA, also termed RNA-binding protein 14 (RBM14), or paraspeckle protein 2 (PSP2), or synaptotagmin-interacting protein (SYT-interacting protein), 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. It stimulates transcription through its interactions with coactivators, such as TRBP and CREB-binding protein CBP/p300, via the TRBP-interacting domain and interaction with an RNA-containing complex, such as DNA-dependent protein kinase-poly(ADP-ribose) polymerase complexes, via the RRMs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 311771527   1 MKIFVGNVDGaDTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGhELRPGRALVVEMS 71
Cdd:cd12608    1 MKIFVGNVDE-DTSQEELSALFEPYGAVLSCAVMKQFAFVHMRGEAAADRAIRELNG-RELHGRALVVEES 69

RNA recognition motif 2 (RRM2) found in vertebrate RRM-containing coactivator activator/modulator (CoAA); This subgroup corresponds to the RRM2 of CoAA, also termed RNA-binding protein 14 (RBM14), or paraspeckle protein 2 (PSP2), or synaptotagmin-interacting protein (SYT-interacting protein), 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. It stimulates transcription through its interactions with coactivators, such as TRBP and CREB-binding protein CBP/p300, via the TRBP-interacting domain and interaction with an RNA-containing complex, such as DNA-dependent protein kinase-poly(ADP-ribose) polymerase complexes, via the RRMs.

                         10        20        30
                 ....*....|....*....|....*....|....*
gi 311771527  79 WKIFVGNVSAACTSQELRSLFERRGRVIECDVVKG 113
Cdd:cd12609    1 WKIFVGNVSATCTSDELRGLFEEFGRVVECDKVKD 35

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 311771527    3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQ-------FAFVHMRENAGALRAIEALHGHELRpGRAL 66
Cdd:pfam00076   1 LFVGNLP-PDTTEEDLKDLFSKFGPIKSIRLVRDetgrskgFAFVEFEDEEDAEKAIEALNGKELG-GREL 69

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

                         10        20        30
                 ....*....|....*....|....*....|...
gi 311771527  80 KIFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:COG0724    3 KIYVGNLPYSVTEEDLRELFSEYGEVTSVKLIT 35

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
                  ....*....|....*....|....*....|..
gi 311771527   81 IFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRLVR 32

RNA recognition motif 1 (RRM1) found in vertebrate RRM-containing coactivator activator/modulator (CoAA); This subgroup corresponds to the RRM1 of CoAA, also termed RNA-binding protein 14 (RBM14), or paraspeckle protein 2 (PSP2), or synaptotagmin-interacting protein (SYT-interacting protein), 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. It stimulates transcription through its interactions with coactivators, such as TRBP and CREB-binding protein CBP/p300, via the TRBP-interacting domain and interaction with an RNA-containing complex, such as DNA-dependent protein kinase-poly(ADP-ribose) polymerase complexes, via the RRMs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 311771527   1 MKIFVGNVDGaDTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGhELRPGRALVVEMS 71
Cdd:cd12608    1 MKIFVGNVDE-DTSQEELSALFEPYGAVLSCAVMKQFAFVHMRGEAAADRAIRELNG-RELHGRALVVEES 69

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

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 311771527   1 MKIFVGNVDgADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVEMSR 72
Cdd:COG0724    2 MKIYVGNLP-YSVTEEDLRELFSEYGEVTSVKLItdretgrsRGFGFVEMPDDEEAQAAIEALNGAELM-GRTLKVNEAR 79

                 ...
gi 311771527  73 PRP 75
Cdd:COG0724   80 PRE 82

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
                 ....*....|....*....|....*....|...
gi 311771527  80 KIFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:cd12343    1 KIFVGNLPDAATSEELRALFEKYGKVTECDIVK 33

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 311771527     2 KIFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQ--------FAFVHMRENAGALRAIEALHGHELRpGRALVV 68
Cdd:smart00360   1 TLFVGNLP-PDTTEEELRELFSKFGKVESVRLVRDketgkskgFAFVEFESEEDAEKALEALNGKELD-GRPLKV 73

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 311771527   3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVM-------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd00590    1 LFVGNLP-PDTTEEDLRELFSKFGEVVSVRIVrdrdgksKGFAFVEFESPEDAEKALEALNGTELG-GRPLKVS 72

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 311771527    3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQ-------FAFVHMRENAGALRAIEALHGHELRpGRAL 66
Cdd:pfam00076   1 LFVGNLP-PDTTEEDLKDLFSKFGPIKSIRLVRDetgrskgFAFVEFEDEEDAEKAIEALNGKELG-GREL 69

RNA recognition motif 1 (RRM1) found in vertebrate RNA-binding protein 4 (RBM4); This subgroup corresponds to the RRM1 of RBM4, a ubiquitously expressed splicing factor that has two isoforms, RBM4A (also known as Lark homolog) and RBM4B (also known as RBM30), which are very similar in structure and sequence. RBM4 may function as a translational regulator of stress-associated mRNAs and also plays a role in micro-RNA-mediated gene regulation. RBM4 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a CCHC-type zinc finger, and three alanine-rich regions within their C-terminal regions. The C-terminal region may be crucial for nuclear localization and protein-protein interaction. The RRMs, in combination with the C-terminal region, are responsible for the splicing function of RBM4.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 311771527   1 MKIFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12606    1 VKLFIGNLP-REATEEEIRSLFEQYGKVTECDIIKNYGFVHMEDKSAADEAIRNLHHYKLH-GVAINVE 67

RNA recognition motif 3 (RRM3) found found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM3 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is an ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 311771527   3 IFVGNVdGADTTPEELAALFAPYGTVMSCAVM-------KQFAFVHMRENAGALRAIEALHGHELRpGRALVV 68
Cdd:cd12380    4 VYVKNF-GEDVDDDELKELFEKYGKITSAKVMkddsgksKGFGFVNFENHEAAQKAVEELNGKELN-GKKLYV 74

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein R (hnRNP R) and similar proteins; This subfamily corresponds to the RRM3 in hnRNP R, hnRNP Q, and APOBEC-1 complementation factor (ACF). hnRNP R is a ubiquitously expressed nuclear RNA-binding protein that specifically bind mRNAs with a preference for poly(U) stretches and has been implicated in mRNA processing and mRNA transport, and also acts as a regulator to modify binding to ribosomes and RNA translation. hnRNP Q is also a ubiquitously expressed nuclear RNA-binding protein. It has been identified as a component of the spliceosome complex, as well as a component of the apobec-1 editosome, and has been implicated in the regulation of specific mRNA transport. ACF is an RNA-binding subunit of a core complex that interacts with apoB mRNA to facilitate C to U RNA editing. It may also act as an apoB mRNA recognition factor and chaperone and play a key role in cell growth and differentiation. This family also includes two functionally unknown RNA-binding proteins, RBM46 and RBM47. All members contain three conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 311771527  12 DTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGHELRpGRALVVEMSRP 73
Cdd:cd12251   12 STTEEKLRELFSEYGKVERVKKIKDYAFVHFEERDDAVKAMEEMNGKELE-GSEIEVSLAKP 72

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 311771527   2 KIFVGNVdGADTTPEELAALFAPYGTVMSCAVMKQ--FAFVHMRENAGALRAIEALHG 57
Cdd:cd12340    1 RLFVRPF-PPDTSESAIREIFSPYGPVKEVKMLSDsnFAFVEFEELEDAIRAKDSVHG 57

RNA recognition motif 1 (RRM1) found in plant Mei2-like proteins; This subgroup corresponds to the RRM1 of Mei2-like proteins that represent an ancient eukaryotic RNA-binding proteins family. Their corresponding Mei2-like genes appear to have arisen early in eukaryote evolution, been lost from some lineages such as Saccharomyces cerevisiae and metazoans, and diversified in the plant lineage. The plant Mei2-like genes may function in cell fate specification during development, rather than as stimulators of meiosis. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RRM (RRM3) is unique to Mei2-like proteins and it is highly conserved between plants and fungi. Up to date, the intracellular localization, RNA target(s), cellular interactions and phosphorylation states of Mei2-like proteins in plants remain unclear.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 311771527   3 IFVGNVDgADTTPEELAALFAPYG---TVMSCAVMKQFAFVHMRENAGALRAIEALHGHELRpGRALVVEMSRPR 74
Cdd:cd12524    4 LFVRNIN-SSVEDEELRALFEQFGeirTLYTACKHRGFIMVSYYDIRAAQSAKRALQGTELG-GRKLDIHFSIPK 76

RNA recognition motif 2 (RRM2) found in yeast nucleolar protein 13 (Nop13p) and similar proteins; This subfamily corresponds to the RRM2 of Nop13p encoded by YNL175c from Saccharomyces cerevisiae. It shares high sequence similarity with nucleolar protein 12 (Nop12p). Both Nop12p and Nop13p are not essential for growth. However, unlike Nop12p that is localized to the nucleolus, Nop13p localizes primarily to the nucleolus but is also present in the nucleoplasm to a lesser extent. Nop13p contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 311771527   3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12397    1 LFVGNLS-FETTEEDLRKHFAPAGKIRKVRMAtfedsgkcKGFAFVDFKEIESATNAVKGPINHSLN-GRDLRVE 73

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        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 311771527   2 KIFVGNVDgADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVEMSRP 73
Cdd:cd21609    1 RLYVGNIP-RNVTSEELAKIFEEAGTVEIAEVMydrytgrsRGFGFVTMGSVEDAKAAIEKLNGTEVG-GREIKVNITEK 78

                 .
gi 311771527  74 R 74
Cdd:cd21609   79 P 79

RNA recognition motif 2 (RRM2) found in yeast nucleolar protein 4 (Nop4p) and similar proteins; This subgroup corresponds to the RRM2 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 311771527  15 PEELAALFAPYGTVMSCAV-------MKQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12675   15 PVHLKKLFGRYGKVVEATIprkkggkLSGFAFVTMKGRKNAEEALESVNGLEID-GRPVAVD 75

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 311771527   2 KIFVGNVDGAdTTPEELAALFAPYGTVMSCAVMKQF--------AFVHMRENAGALRAIEALHGHELRPG--RALVV 68
Cdd:cd12361    1 KLFVGMIPKT-ASEEDVRPLFEQFGNIEEVQILRDKqtgqskgcAFVTFSTREEALRAIEALHNKKTMPGcsSPLQV 76

RNA recognition motif (RRM) found in vertebrate RNA-binding protein Raly; This subgroup corresponds to the RRM of Raly, also termed autoantigen p542, or heterogeneous nuclear ribonucleoprotein C-like 2, or hnRNP core protein C-like 2, or hnRNP associated with lethal yellow protein homolog, an RNA-binding protein that may play a critical role in embryonic development. It is encoded by Raly, a ubiquitously expressed gene of unknown function. Raly shows a high degree of identity with the 5' sequences of p542 gene encoding autoantigen, which can cross-react with EBNA-1 of the Epstein Barr virus. Raly contains two distinct domains, an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal auxiliary domain that includes a unique glycine/serine-rich stretch.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 311771527   2 KIFVGNVDGADTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGHELrPGRALVVEMS-RPRP 75
Cdd:cd12604    3 RVFIGNLNTAVVKKSDVETIFSKYGRVVGCSVHKGYAFVQYTNERHARAAVIGENGRVL-AGQTLDINMAgEPKP 76

RNA recognition motif 2 (RRM2) found in yeast meiotic activator RIM4 and similar proteins; This subfamily corresponds to the RRM2 of RIM4, also termed regulator of IME2 protein 4, a putative RNA binding protein that is expressed at elevated levels early in meiosis. It functions as a meiotic activator required for both the IME1- and IME2-dependent pathways of meiotic gene expression, as well as early events of meiosis, such as meiotic division and recombination, in Saccharomyces cerevisiae. RIM4 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The family also includes a putative RNA-binding protein termed multicopy suppressor of sporulation protein Msa1. It is a putative RNA-binding protein encoded by a novel gene, msa1, from the fission yeast Schizosaccharomyces pombe. Msa1 may be involved in the inhibition of sexual differentiation by controlling the expression of Ste11-regulated genes, possibly through the pheromone-signaling pathway. Like RIM4, Msa1 also contains two RRMs, both of which are essential for the function of Msa1.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 311771527   3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQ------FAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12454    6 IFVGQLD-PKTTDSELFRRFSKYGKIVDCKLIKRpepvnaFAFLRFESEEAAEAAVEEENHSEFL-NKQIRVQ 76

RNA recognition motif 3 (RRM3) found in the Hu proteins family; This subfamily corresponds to the RRM3 of the Hu proteins family which represent a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is the ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 311771527   3 IFVGNVdGADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVV 68
Cdd:cd12377    2 IFVYNL-APDADESLLWQLFGPFGAVQNVKIIrdfttnkcKGYGFVTMTNYDEAAVAIASLNGYRLG-GRVLQV 73

RNA recognition motif (RRM) found in vertebrate heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNP C1/C2); This subgroup corresponds to the RRM of heterogeneous nuclear ribonucleoprotein C (hnRNP) proteins C1 and C2, produced by a single coding sequence. They are the major constituents of the heterogeneous nuclear RNA (hnRNA) ribonucleoprotein (hnRNP) complex in vertebrates. They bind hnRNA tightly, suggesting a central role in the formation of the ubiquitous hnRNP complex. They are involved in the packaging of hnRNA in the nucleus and in processing of pre-mRNA such as splicing and 3'-end formation. hnRNP C proteins contain two distinct domains, an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal auxiliary domain that includes the variable region, the basic region and the KSG box rich in repeated Lys-Ser-Gly sequences, the leucine zipper, and the acidic region. The RRM is capable of binding poly(U). The KSG box may bind to RNA. The leucine zipper may be involved in dimer formation. The acidic and hydrophilic C-teminus harbors a putative nucleoside triphosphate (NTP)-binding fold and a protein kinase phosphorylation site.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 311771527   2 KIFVGNVDGADTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGHELrPGRALVVEMS-RPRP 75
Cdd:cd12603    8 RVFIGNLNTLVVKKSDVEAIFSKYGKIVGCSVHKGFAFVQYVNERNARAAVAGEDGRMI-AGQVLDINLAaEPKV 81

RNA recognition motif 1 (RRM1) found in the p54nrb/PSF/PSP1 family; This subfamily corresponds to the RRM1 of the p54nrb/PSF/PSP1 family, including 54 kDa nuclear RNA- and DNA-binding protein (p54nrb or NonO or NMT55), polypyrimidine tract-binding protein (PTB)-associated-splicing factor (PSF or POMp100), paraspeckle protein 1 (PSP1 or PSPC1), which are ubiquitously expressed and are conserved in vertebrates. p54nrb is a multi-functional protein involved in numerous nuclear processes including transcriptional regulation, splicing, DNA unwinding, nuclear retention of hyperedited double-stranded RNA, viral RNA processing, control of cell proliferation, and circadian rhythm maintenance. PSF is also a multi-functional protein that binds RNA, single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and many factors, and mediates diverse activities in the cell. PSP1 is a novel nucleolar factor that accumulates within a new nucleoplasmic compartment, termed paraspeckles, and diffusely distributes in the nucleoplasm. The cellular function of PSP1 remains unknown currently. This subfamily also includes some p54nrb/PSF/PSP1 homologs from invertebrate species, such as the Drosophila melanogaster gene no-ontransient A (nonA) encoding puff-specific protein Bj6 (also termed NONA) and Chironomus tentans hrp65 gene encoding protein Hrp65. D. melanogaster NONA is involved in eye development and behavior, and may play a role in circadian rhythm maintenance, similar to vertebrate p54nrb. C. tentans Hrp65 is a component of nuclear fibers associated with ribonucleoprotein particles in transit from the gene to the nuclear pore. All family members contain a DBHS domain (for Drosophila behavior, human splicing), which comprises two conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a charged protein-protein interaction module. PSF has an additional large N-terminal domain that differentiates it from other family members.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 311771527   2 KIFVGNVdGADTTPEELAALFAPYGTVMSCAVMKQ--FAFVHMRENAGALRAIEALHGHELRpGRALVV 68
Cdd:cd12332    3 RLFVGNL-PNDITEEEFKELFQKYGEVSEVFLNKGkgFGFIRLDTRANAEAAKAELDGTPRK-GRQLRV 69

RNA recognition motif (RRM) found in heterogeneous nuclear ribonucleoprotein C (hnRNP C)-related proteins; This subfamily corresponds to the RRM in the hnRNP C-related protein family, including hnRNP C proteins, Raly, and Raly-like protein (RALYL). hnRNP C proteins, C1 and C2, are produced by a single coding sequence. They are the major constituents of the heterogeneous nuclear RNA (hnRNA) ribonucleoprotein (hnRNP) complex in vertebrates. They bind hnRNA tightly, suggesting a central role in the formation of the ubiquitous hnRNP complex; they are involved in the packaging of the hnRNA in the nucleus and in processing of pre-mRNA such as splicing and 3'-end formation. Raly, also termed autoantigen p542, is an RNA-binding protein that may play a critical role in embryonic development. The biological role of RALYL remains unclear. It shows high sequence homology with hnRNP C proteins and Raly. Members of this family are characterized by an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal auxiliary domain. The Raly proteins contain a glycine/serine-rich stretch within the C-terminal regions, which is absent in the hnRNP C proteins. Thus, the Raly proteins represent a newly identified class of evolutionarily conserved autoepitopes.

                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 311771527   2 KIFVGNVDGADTTPEELAALFAPYGTVMSCAVMKQFAFV 40
Cdd:cd12341    2 RIFVGNLPTDQMTKEDLEEIFSKYGKILGISLHKGYGFV 40

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

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 311771527   2 KIFVGNVdGADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEAlHGHELRpGRALVVEMSRP 73
Cdd:cd12330    1 KIFVGGL-APDVTEEEFKEYFEQFGTVVDAVVMldhdtgrsRGFGFVTFDSESAVEKVLSK-GFHELG-GKKVEVKRATP 77

                 .
gi 311771527  74 R 74
Cdd:cd12330   78 K 78

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 311771527  81 IFVGNVSAACTSQELRSLFERRGRVIECDVV------KGM 114
Cdd:cd21605    4 IFVGNLPFDCTWEDLKDHFSQVGEVIRADIVtsrgrhRGM 43

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 311771527   3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12398    3 VFVGNIP-YDATEEQLKEIFSEVGPVVSFRLVtdretgkpKGYGFCEFRDAETALSAVRNLNGYELN-GRPLRVD 75

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 311771527   3 IFVGNVdGADTTPEELAALFAPYGTVMSCAV--MKQFAFVHMRENAGALRAIEALHGHELRpGRAL 66
Cdd:cd12354    3 VYVGNI-TKGLTEALLQQTFSPFGQILEVRVfpDKGYAFIRFDSHEAATHAIVSVNGTIIN-GQAV 66

RNA recognition motif (RRM) found in the scaffold attachment factor (SAFB) family; This subfamily corresponds to the RRM domain of the SAFB family, including scaffold attachment factor B1 (SAFB1), scaffold attachment factor B2 (SAFB2), SAFB-like transcriptional modulator (SLTM), and similar proteins, which are ubiquitously expressed. SAFB1, SAFB2 and SLTM have been implicated in many diverse cellular processes including cell growth and transformation, stress response, and apoptosis. They share high sequence similarities and all contain a scaffold attachment factor-box (SAF-box, also known as SAP domain) DNA-binding motif, an RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a region rich in glutamine and arginine residues. SAFB1 is a nuclear protein with a distribution similar to that of SLTM, but unlike that of SAFB2, which is also found in the cytoplasm. To a large extent, SAFB1 and SLTM might share similar functions, such as the inhibition of an oestrogen reporter gene. The additional cytoplasmic localization of SAFB2 implies that it could play additional roles in the cytoplasmic compartment which are distinct from the nuclear functions shared with SAFB1 and SLTM.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 311771527   2 KIFVGNVDgADTTPEELAALFAPYGTVMSCAVM--------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVE 69
Cdd:cd12417    1 NLWISGLS-DTTKAADLKKIFSKYGKVVSAKVVtsartpgsRCYGYVTMASVEEADLCIKSLNKTELH-GRVITVE 74

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        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 311771527   3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVMKQ-----------FAFVHMRENAGALRAIEALHGHELRpGRALVVEMS 71
Cdd:cd12318    3 LFVKNLN-FKTTEEALKKHFEKCGPIRSVTIAKKkdpkgpllsmgYGFVEFKSPEAAQKALKQLQGTVLD-GHALELKIS 80

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
                 ....*....|....*....|....*....|..
gi 311771527  81 IFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:cd00590    1 LFVGNLPPDTTEEDLRELFSKFGEVVSVRIVR 32

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 311771527    3 IFVGNVDgADTTPEELAALFAPYGTVMSCAVM-------KQFAFVHMRENAGALRAIEALHGHELRpGRALVVE--MSRP 73
Cdd:TIGR01628  91 IFVKNLD-KSVDNKALFDTFSKFGNILSCKVAtdengksRGYGFVHFEKEESAKAAIQKVNGMLLN-DKEVYVGrfIKKH 168

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 311771527   74 RPLNT-----WKIFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:TIGR01628 169 EREAAplkkfTNLYVKNLDPSVNEDKLRELFAKFGEITSAAVMK 212

RNA recognition motif;

                           10        20        30
                   ....*....|....*....|....*....|...
gi 311771527    80 KIFVGNVSAACTSQELRSLFERRGRVIECDVVK 112
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVR 33

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 311771527  12 DTTPEELAALFAPYGTVMSCAV-------MKQFAFVHMRENAGALRAIEALHGHELRpGRALVV 68
Cdd:cd12414   10 KCTEDDLKKLFSKFGKVLEVTIpkkpdgkLRGFAFVQFTNVADAAKAIKGMNGKKIK-GRPVAV 72

RNA recognition motif 2 (RRM2) found in Arabidopsis thaliana arginine/serine-rich-splicing factor RSp31 and similar proteins from plants; This subgroup corresponds to the RRM2 in a family that represents a novel group of arginine/serine (RS) or serine/arginine (SR) splicing factors existing in plants, such as A. thaliana RSp31, RSp35, RSp41 and similar proteins. Like vertebrate RS splicing factors, these proteins function as plant splicing factors and play crucial roles in constitutive and alternative splicing in plants. They all contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), at their N-terminus, and an RS domain at their C-terminus.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 311771527   3 IFVGNVDGADTTPEELAALFAPYGTVMSCAVMKQFAFVHMRENAGALRAIEALHGHEL 60
Cdd:cd12466    2 LFVINFDPIRTKERDLERHFEPYGKVVNVRIRRNFAFVQYETQEDATKALDATQSSKI 59

RNA recognition motif (RRM) found in SR-related and CTD-associated factor 4 (SCAF4), SR-related and CTD-associated factor 8 (SCAF8) and similar proteins; This subfamily corresponds to the RRM in a new class of SCAFs (SR-like CTD-associated factors), including SCAF4, SCAF8 and similar proteins. The biological role of SCAF4 remains unclear, but it shows high sequence similarity to SCAF8 (also termed CDC5L complex-associated protein 7, or RNA-binding motif protein 16, or CTD-binding SR-like protein RA8). SCAF8 is a nuclear matrix protein that interacts specifically with a highly serine-phosphorylated form of the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II (pol II). The pol II CTD plays a role in coupling transcription and pre-mRNA processing. In addition, SCAF8 co-localizes primarily with transcription sites that are enriched in nuclear matrix fraction, which is known to contain proteins involved in pre-mRNA processing. Thus, SCAF8 may play a direct role in coupling with both, transcription and pre-mRNA processing, processes. SCAF8 and SCAF4 both contain a conserved N-terminal CTD-interacting domain (CID), an atypical RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNPs (ribonucleoprotein domain), and serine/arginine-rich motifs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 311771527   3 IFVGNVDGAdTTPEELAALFAPYGTVMSCAVM--KQFAFVHMRENAGALRAIEALHGHELR 61
Cdd:cd12227    5 LWVGHLSKK-VTQEELKNLFEEYGEIQSIDMIppRGCAYVCMKTRQDAHRALQKLKNHKLR 64

RNA recognition motif 1 (RRM1) found in plant flowering time control protein FCA and similar proteins; This subgroup corresponds to the RRM1 of FCA, a gene controlling flowering time in Arabidopsis, encoding a flowering time control protein that functions in the posttranscriptional regulation of transcripts involved in the flowering process. FCA contains two RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNP (ribonucleoprotein domains), and a WW protein interaction domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 311771527   2 KIFVGNVDGAdTTPEELAALFAPYGTVMSCAVMK------QFA--FVHMRENAGALRAIEALHGHELRPGRALVVEM 70
Cdd:cd12633    1 KLFVGSVPRT-ITEQEVRPMFEEHGNVLEVAIIKdkrtghQQGccFVKYSTRDEADRAIRALHNQRTLPGGASPVQV 76