Catalytic domain of the Serine/Threonine Kinase, Serine-aRginine Protein Kinase 3
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. SRPK3 is highly expressed in the heart and skeletal muscles, and is controlled by a muscle-specific enhancer that is regulated by MEF2. It may play an important role in muscle development. SRPKs phosphorylate and regulate splicing factors from the SR protein family by specifically phosphorylating multiple serine residues residing in SR/RS dipeptide motifs (also known as RS domains). Phosphorylation of the RS domains enhances interaction with transportin SR and facilitates entry of the SR proteins into the nucleus. SRPKs contain a nonconserved insert domain, within the well-conserved catalytic kinase domain, that regulates their subcellular localization. The SRPK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.
Comment:includes ATP binding and substrate binding sites
Comment:based on the structures of human CDK2 and DYRK1A bound with ATP or inhibitor and substrate peptides, and on the structures of other CMGC kinases, bound with ATP or ATP analogs
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