InterPro domain: IPR039430

Thymidylate kinase ( 2.7.4.9 ; dTMP kinase) catalyzes the phosphorylation of thymidine 5'-monophosphate (dTMP) to form thymidine 5'-diphosphate (dTDP) in the presence of ATP and magnesium:

ATP + thymidine 5'-phosphate = ADP + thymidine 5'-diphosphate

Thymidylate kinase is an ubiquitous enzyme of about 25 Kd and is important in the dTTP synthesis pathway for DNA synthesis. The function of dTMP kinase in eukaryotes comes from the study of a cell cycle mutant, cdc8, in Saccharomyces cerevisiae. Structural and functional analyses suggest that the cDNA codes for authentic human dTMP kinase. The mRNA levels and enzyme activities corresponded to cell cycle progression and cell growth stages [ 1 ].

This entry represents a domain found in thymidylate kinase and mitochondrial UMP-CMP kinase.

From a phylogenetic analysis, human mitochondrial UMP-CMP kinase has been shown to be closer to thymidylate kinase than to cytosolic UMP-CMP kinase. It phosphorylates dUMP, dCMP, CMP, and UMP with ATP as phosphate donor [ 2 ].

1. Human dTMP kinase: gene expression and enzymatic activity coinciding with cell cycle progression and cell growth. DNA Cell Biol. 13, 461-71
2. Human UMP-CMP kinase 2, a novel nucleoside monophosphate kinase localized in mitochondria. J. Biol. Chem. 283, 1563-71