The deoxycytidine pathway for thymidylate synthesis in Escherichia coli

When thymidylate production is diminished by a mutation affecting dCTP deaminase, Escheriehia coli is known to use an alternate pathway involving deoxycytidine as an intermediate. The pathway requires the gene for any of three nucleoside diphosphate kinases (ndk, pykA, or pykF) and the gene for a 5'-nucleotidase (yfbR).