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).

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                ....*....|....*....|....*....|....*....|....*....|....
gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAFPRRAQPK 54
Cdd:cd12760  35 MVMRDPTTKRSRGFGFVTFADPASVDKVLAQPHHELDSKTIDPKVAFPRRAQPK 88

RNA recognition motif 1 (RRM1) found in RNA-binding protein Musashi homolog 2 (Musashi-2 ) and similar proteins; This subgroup corresponds to the RRM2 of Musashi-2 (also termed Msi2) which has been identified as a regulator of the hematopoietic stem cell (HSC) compartment and of leukemic stem cells after transplantation of cells with loss and gain of function of the gene. It influences proliferation and differentiation of HSCs and myeloid progenitors, and further modulates normal hematopoiesis and promotes aggressive myeloid leukemia. Musashi-2 contains two conserved N-terminal tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), along with other domains of unknown function.

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                ....*....|....*....|....*....|....*....|....*....|....
gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAFPRRAQPK 54
Cdd:cd12760  35 MVMRDPTTKRSRGFGFVTFADPASVDKVLAQPHHELDSKTIDPKVAFPRRAQPK 88

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

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                ....*....|....*....|....*....|....*....|....*....|....*...
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPH-HELDSKTIdpKVafpRRAQPKSSRA 58
Cdd:COG0724  33 LITDRETGRSRGFGFVEMPDDEEAQAAIEALNgAELMGRTL--KV---NEARPREERP 85

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
                 ....*....|....*....|....*....|....*....|.
gi 149053822   2 VMRDPTtKRSRGFGFVTFADPASVDKVLGQ-PHHELDSKTI 41
Cdd:pfam00076 30 LVRDET-GRSKGFAFVEFEDEEDAEKAIEAlNGKELGGREL 69

RNA recognition motif 1 (RRM1) found in RNA-binding protein Musashi homolog 2 (Musashi-2 ) and similar proteins; This subgroup corresponds to the RRM2 of Musashi-2 (also termed Msi2) which has been identified as a regulator of the hematopoietic stem cell (HSC) compartment and of leukemic stem cells after transplantation of cells with loss and gain of function of the gene. It influences proliferation and differentiation of HSCs and myeloid progenitors, and further modulates normal hematopoiesis and promotes aggressive myeloid leukemia. Musashi-2 contains two conserved N-terminal tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), along with other domains of unknown function.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAFPRRAQPK 54
Cdd:cd12760  35 MVMRDPTTKRSRGFGFVTFADPASVDKVLAQPHHELDSKTIDPKVAFPRRAQPK 88

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

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                ....*....|....*....|....*....|....*....|...
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPK 44
Cdd:cd12325  30 VMKDPATGRSRGFGFVTFKDPSSVDAVLAARPHTLDGRTIDPK 72

RNA recognition motif 1 (RRM1) 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.

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                ....*....|....*....|....*....|....*....|....*...
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHeLDSKTIDPKVAFPR 49
Cdd:cd12577  30 IMKDSATGRSRGFGFLTFEDPSSVNEVMKKEHV-LDGKIIDPKRAIPR 76

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein A/B (hnRNP A/B) and similar proteins; This subgroup corresponds to the RRM1 of hnRNP A/B, also termed APOBEC1-binding protein 1 (ABBP-1), which is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus plays an important role in apoB mRNA editing. hnRNP 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.

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                ....*....|....*....|....*....|....*....|..
gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12757  39 DPNTGRSRGFGFILFKDAASVDKVLEQKEHRLDGRVIDPKKA 80

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins; This subfamily corresponds to the RRM1 in hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins. hnRNP D0 is a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP A/B is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus plays an important role in apoB mRNA editing. hnRNP DL (or hnRNP D-like) is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. All members in this family contain two putative RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glycine- and tyrosine-rich C-terminus.

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                ....*....|....*....|....*....|....*....|
gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPK 44
Cdd:cd12575  33 DPVTGRSRGFGFVLFKDAESVDKVLDQKEHKLDGKVIDPK 72

RNA recognition motif 1 (RRM1) found in Deleted in azoospermia-associated protein 1 (DAZAP1) and similar proteins; This subfamily corresponds to the RRM1 of DAZAP1 or DAZ-associated protein 1, also termed proline-rich RNA binding protein (Prrp), a multi-functional ubiquitous RNA-binding protein expressed most abundantly in the testis and essential for normal cell growth, development, and spermatogenesis. DAZAP1 is a shuttling protein whose acetylated form is predominantly nuclear and the nonacetylated form is in cytoplasm. It also functions as a translational regulator that activates translation in an mRNA-specific manner. DAZAP1 was initially identified as a binding partner of Deleted in Azoospermia (DAZ). It also interacts with numerous hnRNPs, including hnRNP U, hnRNP U like-1, hnRNPA1, hnRNPA/B, and hnRNP D, suggesting DAZAP1 might associate and cooperate with hnRNP particles to regulate adenylate-uridylate-rich elements (AU-rich element or ARE)-containing mRNAs. DAZAP1 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal proline-rich domain.

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                ....*....|....*....|....*....|....*....|....*....|...
gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAFPRRAQP 53
Cdd:cd12574  30 VIMKDKTTNQSRGFGFVKFKDPNCVGTVLASRPHNLDGRNIDPKPCTPRGMQP 82

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein D0 (hnRNP D0) and similar proteins; This subgroup corresponds to the RRM1 of hnRNP D0, also termed AU-rich element RNA-binding protein 1, which is a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP D0 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), in the middle and an RGG box rich in glycine and arginine residues in the C-terminal part. Each of RRMs can bind solely to the UUAG sequence specifically.

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                ....*....|....*....|....*....|....*....|..
gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12756  33 DPITGRSRGFGFVLFKESESVDKVMDQKEHKLNGKVIDPKRA 74

RNA recognition motif 2 (RRM2) found in RNA-binding protein Musashi homologs Musashi-1, Musashi-2 and similar proteins; This subfamily corresponds to the RRM2.in Musashi-1 (also termed Msi1), a neural RNA-binding protein putatively expressed in central nervous system (CNS) stem cells and neural progenitor cells, and associated with asymmetric divisions in neural progenitor cells. It is evolutionarily conserved from invertebrates to vertebrates. Musashi-1 is a homolog of Drosophila Musashi and Xenopus laevis nervous system-specific RNP protein-1 (Nrp-1). It has been implicated in the maintenance of the stem-cell state, differentiation, and tumorigenesis. It translationally regulates the expression of a mammalian numb gene by binding to the 3'-untranslated region of mRNA of Numb, encoding a membrane-associated inhibitor of Notch signaling, and further influences neural development. Moreover, Musashi-1 represses translation by interacting with the poly(A)-binding protein and competes for binding of the eukaryotic initiation factor-4G (eIF-4G). Musashi-2 (also termed Msi2) has been identified as a regulator of the hematopoietic stem cell (HSC) compartment and of leukemic stem cells after transplantation of cells with loss and gain of function of the gene. It influences proliferation and differentiation of HSCs and myeloid progenitors, and further modulates normal hematopoiesis and promotes aggressive myeloid leukemia. Both, Musashi-1 and Musashi-2, contain two conserved N-terminal tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), along with other domains of unknown function.

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gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKV 45
Cdd:cd12323  30 MLMFDKQTNRHRGFGFVTFESEDVVDKVCEIHFHEINNKMVECKK 74

RNA recognition motif;

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gi 149053822    2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPH-HELDSKTID 42
Cdd:smart00360 31 LVRDKETGKSKGFAFVEFESEEDAEKALEALNgKELDGRPLK 72

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.

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gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPK 44
Cdd:cd12328  31 IVTDKETGKKRGFAFVTFDDHDSVDKIVLQKYHTINGHRCEVK 73

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein A3 (hnRNP A3) and similar proteins; This subgroup corresponds to the RRM2 of hnRNP A3, a novel RNA trafficking response element-binding protein that interacts with the hnRNP A2 response element (A2RE) independently of hnRNP A2 and participates in the trafficking of A2RE-containing RNA. hnRNP A3 can shuttle between the nucleus and the cytoplasm. It contains 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.

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gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAFPRR 50
Cdd:cd12582  32 VMEDRQSGKKRGFAFVTFDDHDTVDKIVVQKYHTINGHNCEVKKALSKQ 80

RNA recognition motif 2 (RRM2) found in RNA-binding protein Musashi homolog 2 (Musashi-2) and similar proteins; This subgroup corresponds to the RRM2 of Musashi-2 (also termed Msi2) which has been identified as a regulator of the hematopoietic stem cell (HSC) compartment and of leukemic stem cells after transplantation of cells with loss and gain of function of the gene. It influences proliferation and differentiation of HSCs and myeloid progenitors, and further modulates normal hematopoiesis and promotes aggressive myeloid leukemia. Musashi-2 contains two conserved N-terminal tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), along with other domains of unknown function.

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gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12573  31 MLMFDKTTNRHRGFGFVTFENEDVVEKVCEIHFHEINNKMVECKKA 76

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins; This subfamily corresponds to the RRM2 of hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins. hnRNP D0, a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP A/B is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. It has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus plays an important role in apoB mRNA editing. hnRNP DL (or hnRNP D-like) is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. All memembers in this family contain two putative RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glycine- and tyrosine-rich C-terminus.

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                ....*....|....*....|....*....|....*....|....*.
gi 149053822  1 MVMrDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12329  31 LPM-DKKTNKRRGFCFITFDSEEPVKKILETQFHVIGGKKVEVKKA 75

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

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                ....*....|....*....|....*....|
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQ 31
Cdd:cd12284  30 LQKDPETGRSKGYGFIQFRDAEDAKKALEQ 59

RNA recognition motif 3 (RRM3) found in CELF/Bruno-like family of RNA binding proteins CELF1, CELF2, CELF3, CELF4, CELF5, CELF6 and similar proteins; This subgroup corresponds to the RRM3 of the CUGBP1 and ETR-3-like factors (CELF) or BRUNOL (Bruno-like) proteins, a family of structurally related RNA-binding proteins involved in the regulation of pre-mRNA splicing in the nucleus and in the control of mRNA translation and deadenylation in the cytoplasm. The family contains six members: CELF-1 (also termed BRUNOL-2, or CUG-BP1, or NAPOR, or EDEN-BP), CELF-2 (also termed BRUNOL-3, or ETR-3, or CUG-BP2, or NAPOR-2), CELF-3 (also termed BRUNOL-1, or TNRC4, or ETR-1, or CAGH4, or ER DA4), CELF-4 (also termed BRUNOL-4), CELF-5 (also termed BRUNOL-5), CELF-6 (also termed 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.

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                ....*....|....*....|....*.
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDK 27
Cdd:cd12362  30 VFVDKNTGRSKGFGFVSYDNPLSAQA 55

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein A0 (hnRNP A0) and similar proteins; This subfamily corresponds to the RRM1 of hnRNP A0 which 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 A0 contains 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.

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                ....*....|....*....|....*....|....*....|....*.
gi 149053822  1 MVMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12326  33 VVVVNPQTKRSRCFGFVTYSSAEEADAAMAAAPHVVDGNNVELKRA 78

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.

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gi 149053822  2 VMRDPTTKrSRGFGFVTFADPASVDKVLgqphHELDSKTIDPKVAFPRRAQPK 54
Cdd:cd12380  33 VMKDDSGK-SKGFGFVNFENHEAAQKAV----EELNGKELNGKKLYVGRAQKK 80

RNA recognition motif (RRM) found in RNA-binding protein 42 (RBM42) and similar proteins; This subfamily corresponds to the RRM of RBM42 which has been identified as a heterogeneous nuclear ribonucleoprotein K (hnRNP K)-binding protein. It also directly binds the 3' untranslated region of p21 mRNA that is one of the target mRNAs for hnRNP K. Both, hnRNP K and RBM42, are components of stress granules (SGs). Under nonstress conditions, RBM42 predominantly localizes within the nucleus and co-localizes with hnRNP K. Under stress conditions, hnRNP K and RBM42 form cytoplasmic foci where the SG marker TIAR localizes, and may play a role in the maintenance of cellular ATP level by protecting their target mRNAs. RBM42 contains an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

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                ....*....|....*....|....*....|....*....|
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLgqphHELDSKTI 41
Cdd:cd12383  38 VIRDKRTGKSKGYGFVSFKDPNDYLKAL----REMNGKYV 73

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
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gi 149053822    2 VMRDPTtKRSRGFGFVTFADPASVDKVLgqphHELDSKTID----PKVAFPRRAQPKSSR 57
Cdd:TIGR01628 210 VMKDGS-GRSRGFAFVNFEKHEDAAKAV----EEMNGKKIGlakeGKKLYVGRAQKRAER 264

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        30
                ....*....|....*....|....*....|....*..
gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTI 41
Cdd:cd12400  35 DKKTGKSKGCAFVEFDNQKALQKALKLHHTSLGGRKI 71

RNA recognition motif 2 (RRM2) found in splicing factor 3B subunit 4 (SF3B4) and similar proteins; This subfamily corresponds to the RRM2 of SF3B4, also termed pre-mRNA-splicing factor SF3b 49 kDa (SF3b50), or spliceosome-associated protein 49 (SAP 49). SF3B4 is a component of the multiprotein complex splicing factor 3b (SF3B), an integral part of the U2 small nuclear ribonucleoprotein (snRNP) and the U11/U12 di-snRNP. SF3B is essential for the accurate excision of introns from pre-messenger RNA, and is involved in the recognition of the pre-mRNA's branch site within the major and minor spliceosomes. SF3B4 functions to tether U2 snRNP with pre-mRNA at the branch site during spliceosome assembly. It is an evolutionarily highly conserved protein with orthologs across diverse species. SF3B4 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It binds directly to pre-mRNA and also interacts directly and highly specifically with another SF3B subunit called SAP 145.

                        10
                ....*....|....*....
gi 149053822  2 VMRDPTTKRSRGFGFVTFA 20
Cdd:cd12335  34 IMRDPDTGNSKGFGFVSFD 52

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and similar proteins; This subgroup corresponds to the RRM2 of hnRNP A1, also termed helix-destabilizing protein, or single-strand RNA-binding protein, or hnRNP core protein A1, an abundant eukaryotic nuclear RNA-binding protein that may modulate splice site selection in pre-mRNA splicing. hnRNP A1 has been characterized as a splicing silencer, often acting in opposition to an activating hnRNP H. It silences exons when bound to exonic elements in the alternatively spliced transcripts of c-src, HIV, GRIN1, and beta-tropomyosin. hnRNP A1 can shuttle between the nucleus and the cytoplasm. Thus, it may be involved in transport of cellular RNAs, including the packaging of pre-mRNA into hnRNP particles and transport of poly A+ mRNA from the nucleus to the cytoplasm. The cytoplasmic hnRNP A1 has high affinity with AU-rich elements, whereas the nuclear hnRNP A1 has high affinity with a polypyrimidine stretch bordered by AG at the 3' ends of introns. hnRNP A1 is also involved in the replication of an RNA virus, such as mouse hepatitis virus (MHV), through an interaction with the transcription-regulatory region of viral RNA. Moreover, hnRNP A1, together with the scaffold protein septin 6, serves as host proteins to form a complex with NS5b and viral RNA, and further play important roles in the replication of Hepatitis C virus (HCV). hnRNP A1 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long glycine-rich region at the C-terminus. The RRMs of hnRNP A1 play an important role in silencing the exon and the glycine-rich domain is responsible for protein-protein interactions.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVAF 47
Cdd:cd12580  32 IMTDRGSGKKRGFAFVTFDDHDSVDKIVIQKYHTVNGHNCEVRKAL 77

RNA recognition motif (RRM) found in eukaryotic RNA-binding protein RBM24, RBM38 and similar proteins; This subfamily corresponds to the RRM of RBM24 and RBM38 from vertebrate, SUPpressor family member SUP-12 from Caenorhabditis elegans and similar proteins. Both, RBM24 and RBM38, are preferentially expressed in cardiac and skeletal muscle tissues. They regulate myogenic differentiation by controlling the cell cycle in a p21-dependent or -independent manner. RBM24, also termed RNA-binding region-containing protein 6, interacts with the 3'-untranslated region (UTR) of myogenin mRNA and regulates its stability in C2C12 cells. RBM38, also termed CLL-associated antigen KW-5, or HSRNASEB, or RNA-binding region-containing protein 1(RNPC1), or ssDNA-binding protein SEB4, is a direct target of the p53 family. It is required for maintaining the stability of the basal and stress-induced p21 mRNA by binding to their 3'-UTRs. It also binds the AU-/U-rich elements in p63 3'-UTR and regulates p63 mRNA stability and activity. SUP-12 is a novel tissue-specific splicing factor that controls muscle-specific splicing of the ADF/cofilin pre-mRNA in C. elegans. All family members contain a conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                        10        20
                ....*....|....*....|....*.
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDK 27
Cdd:cd12384  32 VITDRQTGKSRGYGFVTMADREAAER 57

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
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gi 149053822  2 VMRDPTTKRSRGFGFVT 18
Cdd:cd21609  31 VMYDRYTGRSRGFGFVT 47

RNA recognition motif 1 (RRM1) found in vertebrate Hu-antigen C (HuC); This subgroup corresponds to the RRM1 of HuC, also termed ELAV-like protein 3 (ELAV-3), or paraneoplastic cerebellar degeneration-associated antigen, or paraneoplastic limbic encephalitis antigen 21 (PLE21), one of the neuronal members of the Hu family. The neuronal Hu proteins play important roles in neuronal differentiation, plasticity and memory. Like other Hu proteins, HuC contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an AU-rich RNA element (ARE). The AU-rich element binding of HuC can be inhibited by flavonoids. 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
                ....*....|....*....|....*....|....*....|....*....
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVLGQPHH-ELDSKTIdpKVAFPR 49
Cdd:cd12772  36 LVRDKITGQSLGYGFVNYVDPNDADKAINTLNGlKLQTKTI--KVSYAR 82

RNA recognition motif 2 (RRM2) found in heterogeneous nuclear ribonucleoprotein D-like (hnRNP DL) and similar proteins; This subgroup corresponds to the RRM2 of hnRNP DL (or hnRNP D-like), also termed AU-rich element RNA-binding factor, or JKT41-binding protein (protein laAUF1 or JKTBP), is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. hnRNP DL binds single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) in a non-sequencespecific manner, and interacts with poly(G) and poly(A) tenaciously. It contains two putative two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glycine- and tyrosine-rich C-terminus.

                        10        20        30        40
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gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12585  34 DTKTNERRGFCFITYTDEEPVQKLLESRYHQIGSGKCEIKVA 75

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
                ....*....|....*....|....*....|....*....|..
gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHHELDSKTIDPKVA 46
Cdd:cd12584  39 DPKTNKRRGFVFITFKEEDPVKKILEKKFHNVSGSKCEIKIA 80

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

                        10        20
                ....*....|....*....|....*...
gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVL 29
Cdd:cd12395  31 IVRDRETGIGKGFGYVLFKDKDSVDLAL 58

RNA recognition motif 4 (RRM4) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM4 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in theThe CD corresponds to the RRM. regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is an ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. Moreover, PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

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gi 149053822  2 VMRDPTTkRSRGFGFVTFADPASVDKVLgqphHELDSKTIDPK---VAFPRR 50
Cdd:cd12381  33 VMTDEGG-RSKGFGFVCFSSPEEATKAV----TEMNGRIIGGKplyVALAQR 79

RNA recognition motif 2 (RRM2) found in TAR DNA-binding protein 43 (TDP-43) and similar proteins; This subfamily corresponds to the RRM2 of TDP-43 (also termed TARDBP), a ubiquitously expressed pathogenic protein whose normal function and abnormal aggregation are directly linked to the genetic disease cystic fibrosis, and two neurodegenerative disorders: frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). TDP-43 binds both DNA and RNA, and has been implicated in transcriptional repression, pre-mRNA splicing and translational regulation. TDP-43 is a dimeric protein with two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal glycine-rich domain. The RRMs are responsible for DNA and RNA binding; they bind to TAR DNA and RNA sequences with UG-repeats. The glycine-rich domain can interact with the hnRNP family proteins to form the hnRNP-rich complex involved in splicing inhibition. It is also essential for the cystic fibrosis transmembrane conductance regulator (CFTR) exon 9-skipping activity.

                        10        20
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gi 149053822 12 RGFGFVTFADPASVDKVLGQPH 33
Cdd:cd12322  37 RAFAFVTFADDEVAQSLCGEDH 58

RNA recognition motif 3 (RRM3) found in RNA-binding protein 45 (RBM45) and similar proteins; This subfamily corresponds to the RRM3 of RBM45, also termed developmentally-regulated RNA-binding protein 1 (DRB1), a new member of RNA recognition motif (RRM)-type neural RNA-binding proteins, which expresses under spatiotemporal control. It is encoded by gene drb1 that is expressed in neurons, not in glial cells. RBM45 predominantly localizes in cytoplasm of cultured cells and specifically binds to poly(C) RNA. It could play an important role during neurogenesis. RBM45 carries four RRMs, also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20
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gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASV 25
Cdd:cd12368  31 LKRDPYTGKSKGFAYVTYNNPASA 54

RNA recognition motif (RRM) found in Helicobacter pylori HP0827 protein and similar proteins; This subfamily corresponds to the RRM of H. pylori HP0827, a putative ssDNA-binding protein 12rnp2 precursor, containing one RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The ssDNA binding may be important in activation of HP0827.

                        10        20        30
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gi 149053822  5 DPTTKRSRGFGFVTFADPASVDKVLGQPHH-ELDSKTI 41
Cdd:cd12399  33 DRETKRPRGFGFVELQEEESAEKAIAKLDGtDFMGRTI 70

RNA recognition motif 2 (RRM2) found in yeast negative growth regulatory protein NGR1, yeast protein NAM8 and similar proteins; This subgroup corresponds to the RRM2 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.

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gi 149053822  2 VMRDPTTKRSRGFGFVTFAD 21
Cdd:cd12613  34 IMTDPVTGVSRGYGFVRFSD 53

RNA recognition motif 1 (RRM1) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM1 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is a ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. Moreover, PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammals, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

                        10        20
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gi 149053822  2 VMRDPTTKRSRGFGFVTFADPASVDKVL 29
Cdd:cd12378  31 VCRDAVTRRSLGYAYVNFQQPADAERAL 58

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

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gi 149053822  6 PTTKRSRGFGFVTFADPASVDKVLGqphhELDSKTIDPKVAFPRRAQPKSSRA 58
Cdd:cd21622  41 PGTGISKGFGFVAFSKPEDAAKAKE----TLNGVMVGRKRIFVSYAERKEDRE 89

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

                        10        20
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gi 149053822  2 VMRDPTTKRSRGFGFVTFADP 22
Cdd:cd12408  31 LAKDKETGQSKGFAFVTFETR 51

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
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gi 149053822  2 VMRDPTTKRSRGFGFVTFAD 21
Cdd:cd12377  31 IIRDFTTNKCKGYGFVTMTN 50

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

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gi 149053822    2 VMRDPTTKRSRGFGFVTFAD 21
Cdd:TIGR01622 246 LQKDPETGRSKGYGFIQFRD 265

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

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gi 149053822  1 MVMrDPTTKRSRGFGFVTFADPASVDKVL 29
Cdd:cd12415  32 IVL-DKDTGHSKGTAFVQFKTKESADKCI 59

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

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gi 149053822  2 VMRDPTTKRSRGFGFVTFADP----ASVDKVLGQphhELDSKTI 41
Cdd:cd12447  31 VITDRGSGRSKGYGYVDFATPeaaqKALAAMSGK---EIDGRQI 71

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor SRSF2, SRSF8 and similar proteins; This subfamily corresponds to the RRM of SRSF2 and SRSF8. SRSF2, also termed protein PR264, or splicing component, 35 kDa (splicing factor SC35 or SC-35), is a prototypical SR protein that plays important roles in the alternative splicing of pre-mRNA. It is also involved in transcription elongation by directly or indirectly mediating the recruitment of elongation factors to the C-terminal domain of polymerase II. SRSF2 is exclusively localized in the nucleus and is restricted to nuclear processes. It contains a single N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by a C-terminal RS domain rich in serine-arginine dipeptides. The RRM is responsible for the specific recognition of 5'-SSNG-3' (S=C/G) RNA. In the regulation of alternative splicing events, it specifically binds to cis-regulatory elements on the pre-mRNA. The RS domain modulates SRSF2 activity through phosphorylation, directly contacts RNA, and promotes protein-protein interactions with the spliceosome. SRSF8, also termed SRP46 or SFRS2B, is a novel mammalian SR splicing factor encoded by a PR264/SC35 functional retropseudogene. SRSF8 is localized in the nucleus and does not display the same activity as PR264/SC35. It functions as an essential splicing factor in complementing a HeLa cell S100 extract deficient in SR proteins. Like SRSF2, SRSF8 contains a single N-terminal RRM and a C-terminal RS domain.

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gi 149053822  4 RDPTTKRSRGFGFVTFADPASVDKVLgqphHELDSKTID 42
Cdd:cd12311  32 RDRYTRESRGFAFVRFYDKRDAEDAI----DAMDGAELD 66

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

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gi 149053822 11 SRGFGFVTFADPASVDKVL 29
Cdd:cd12412  42 SKGYGFVTFETQEDAEKIQ 60