Deoxythymidylate Kinase (DTYMK)

Thymidylate kinase (EC 2.7.4.9; ATP:dTMP phosphotransferase) catalyzes the phosphorylation of dTMP to form dTDP in the dTTP synthesis pathway for DNA synthesis. Knowledge of the essential function of dTMP kinase in eukaryotes comes from the study of a cell cycle mutant, cdc8, in Saccharomyces cerevisiae. The product of the cdc8 gene is involved in the elongation step of S phase in cell cycle progression. Huang et al. (1994) cloned the human thymidylate kinase gene by complementation with the cdc8 mutation. The cDNA sequence revealed an open reading frame that encodes a protein with a molecular weight of 23,806. Structural and functional analyses suggested that the cDNA codes for authentic human dTMP kinase. The mRNA levels and enzyme activities corresponded to cell cycle progression and cell growth stages.