2.1.2.B2 | structures of MilA and its complexes with substrates including CMP, dCMP and hydroxymethyl-CMP. Two residues in the active site of dCMP hydroxymethylase from T4 phage and thymidylate synthase from Escherichia coli, a serine and an arginine, are respectively replaced by an alanine and a lysine, Ala176 and Lys133, in MilA |