RNA recognition motif 1 (RRM1) found in plant pre-mRNA-splicing factor SF2 and similar proteins
This subgroup corresponds to the RRM1 of SF2, also termed SR1 protein, a plant serine/arginine (SR)-rich phosphoprotein similar to the mammalian splicing factor SF2/ASF. It promotes splice site switching in mammalian nuclear extracts. SF2 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a C-terminal domain rich in proline, serine and lysine residues (PSK domain), a composition reminiscent of histones. This PSK domain harbors a putative phosphorylation site for the mitotic kinase cyclin/p34cdc2.