has participant hydron ATP(4-) hydroxy group ADP(3-) phosphate group(2-) protein serine/threonine kinase activity RNA polymerase II CTD heptapeptide repeat kinase activity MetaCyc:RNA-POLYMERASE-SUBUNIT-KINASE-RXN [RNA-polymerase]-subunit kinase activity Reactome:R-HSA-167191 GO:0008353 CTD kinase activity molecular_function RNA polymerase subunit kinase activity RHEA:10216 RNA-polymerase-subunit kinase activity RNA polymerase II carboxy-terminal domain kinase activity EC:2.7.11.23 Reactome:R-HSA-170706 Reactome:R-HSA-170704 Catalysis of the reaction: ATP + RNA polymerase II large subunit CTD heptapeptide repeat (consensus YSPTSPS) = ADP + H+ + phosphorylated RNA polymerase II. RNA polymerase II CTD heptapeptide repeat modifying activity