Unique features of human protein arginine methyltransferase 9 (PRMT9) and its substrate RNA splicing factor SF3B2

Abstract

Background: Newly discovered protein arginine methyltransferase 9 (PRMT9) modulates alternative splicing by methylation of SF3B2. Results: Biochemical probes of PRMT9 and its substrate protein revealed domains and residues required for methylation. Conclusion: PRMT9 is unique among PRMTs in its narrow range of methyl-accepting substrates. Significance: Understanding PRMT9 catalysis will help elucidate how it may control the activity of SF3B2 and other potential endogenous substrates.