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
                  ....*....|....*....|....*....|....*....|....*
gi 151301053 1098 CVVSVEGLSSSTTDAQLKSLLMSVGPIQSLQMLPQQRKAIAKFKE 1142
Cdd:cd12689     3 PVVHVRGLSEHVTEADLVEALQNFGPISYVTMMPKKRQALVEFED 47

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein L (hnRNP-L) and similar proteins; This subfamily corresponds to the RRM1 of heterogeneous nuclear ribonucleoprotein L (hnRNP-L), heterogeneous nuclear ribonucleoprotein L-like (hnRNP-LL), and similar proteins. hnRNP-L is a higher eukaryotic specific subunit of human KMT3a (also known as HYPB or hSet2) complex required for histone H3 Lys-36 trimethylation activity. It plays both, nuclear and cytoplasmic, roles in mRNA export of intronless genes, IRES-mediated translation, mRNA stability, and splicing. hnRNP-LL plays a critical and unique role in the signal-induced regulation of CD45 and acts as a global regulator of alternative splicing in activated T cells. It is closely related in domain structure and sequence to hnRNP-L, which contains three RNA-recognition motifs (RRMs), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 151301053 1098 CVVSVEGLSSSTTDAQLKSLLMSVGPIQSLQMLPQQRKAIAKFKE 1142
Cdd:cd12689     3 PVVHVRGLSEHVTEADLVEALQNFGPISYVTMMPKKRQALVEFED 47

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein L (hnRNP-L) and similar proteins; This subfamily corresponds to the RRM1 of heterogeneous nuclear ribonucleoprotein L (hnRNP-L), heterogeneous nuclear ribonucleoprotein L-like (hnRNP-LL), and similar proteins. hnRNP-L is a higher eukaryotic specific subunit of human KMT3a (also known as HYPB or hSet2) complex required for histone H3 Lys-36 trimethylation activity. It plays both, nuclear and cytoplasmic, roles in mRNA export of intronless genes, IRES-mediated translation, mRNA stability, and splicing. hnRNP-LL plays a critical and unique role in the signal-induced regulation of CD45 and acts as a global regulator of alternative splicing in activated T cells. It is closely related in domain structure and sequence to hnRNP-L, which contains three RNA-recognition motifs (RRMs), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 151301053 1098 CVVSVEGLSSSTTDAQLKSLLMSVGPIQSLQMLPQQRKAIAKFKE 1142
Cdd:cd12689     3 PVVHVRGLSEHVTEADLVEALQNFGPISYVTMMPKKRQALVEFED 47

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor 11 (SRSF11), splicing regulatory glutamine/lysine-rich protein 1 (SREK1) and similar proteins; This subfamily corresponds to the RRM domain of SRSF11 (SRp54 or p54), SREK1 ( SFRS12 or SRrp86) and similar proteins, a group of proteins containing regions rich in serine-arginine dipeptides (SR protein family). These are involved in bridge-complex formation and splicing by mediating protein-protein interactions across either introns or exons. SR proteins have been identified as crucial regulators of alternative splicing. Different SR proteins display different substrate specificity, have distinct functions in alternative splicing of different pre-mRNAs, and can even negatively regulate splicing. All SR family members are characterized by the presence of one or two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and the C-terminal regions rich in serine and arginine dipeptides (SR domains). The RRM domain is responsible for RNA binding and specificity in both alternative and constitutive splicing. In contrast, SR domains are thought to be protein-protein interaction domains that are often interchangeable.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 151301053 1099 VVSVEGLSSSTTDAQLKSLLMSVGPIQSLQMLP--------QQRKAIAKFKEPAHALAFQqkfhrHMIDLSHINVALIVE 1170
Cdd:cd12259     1 VVQVTNVSPQATEEQMRTLFGFIGKIEELRLYPseddlapvLSKVCFVKYEDPEDVAVAL-----HLTNTVFIDRALIVI 75