Deoxyuridine phosphates formation

Kornberg s work on the biosynthesis of deoxyribonucleic acid has shown that enzymes in Escherichia coli extracts catalyze the formation of the 5-triphosphates of 2-deoxyadenosine, 2-deoxyguanosine, 2-deoxycyti-dine, and thymidine from the corresponding monophosphates in the presence of adenosine 5-triphosphate, but fail to catalyze phosphorylation of deoxyuridine 5-phosphate this finding could explain why uracil is not a constituent of deoxyribonucleic acid. 

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