Which enzyme activity would be directly reduced if fluorodeoxyuridine- -monophosphate is present?
A) thymidine kinase
B) thymidylate synthase
C) dihydrofolate reductase
D) serine hydroxymethyltransferase

Question

Which enzyme activity would be directly reduced if fluorodeoxyuridine-  -monophosphate is present?
A) thymidine kinase 
B) thymidylate synthase 
C) dihydrofolate reductase 
D) serine hydroxymethyltransferase

Quizplus · Accepted Answer

Fluorodeoxyuridine-5'-monophosphate (FdUMP) is a potent inhibitor of thymidylate synthase (TS), an enzyme that catalyzes the conversion of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP), which is an essential precursor for DNA synthesis. FdUMP forms a covalent complex with TS, thereby blocking the formation of dTMP and inhibiting DNA synthesis. Thus, the direct reduction in enzyme activity will be of thymidylate synthase.

Which Enzyme Activity Would Be Directly Reduced If Fluorodeoxyuridine-