A bacteriophage-induced 5-methyldeoxycytidine 5'-monophosphate kinase.

Bacteriophage XP-12-infected Xanthomonas oryzae have been found to be a source of a kinase preparation which converts m5dCMP to m5dCDP and then to m5dCTP using ATP as the phosphate donor. Optimal formation of the triphosphate required the presence of creatine phosphate and creatine kinase. In the presence of dGTP, dTTP and dATP, Escherichia coli DNA polymerase I and T4 DNA polymerase catalyzed the incorporation of m5dCTP into DNA just as efficiently as that of dCTP. Neither dTMP nor dCMP served as substrate for the m5dCMP monophosphate kinase. Analogous preparations from uninfected X. oryzae were unable to phosphorylate m5dCMP.