The enzymatic synthesis of thymidylate. I. Early steps in the purification of thymidylate synthetase of Escherichia coli.

The formation of thymidine triphosphate in cell-free extracts of Escherichia coli was reported in 1957 to require deoxyuridylate, formaldehyde, dZ,n-tetrahydrofolate, Mg++, and adenosine triphosphate (1). It soon became apparent through use of chromatographic procedures that ATP was not involved in the primary conversion of deoxyuridylate to thymidylate, and that the over-all reaction could be represented as follows.