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.