3.5.4.13 dCTP + H2O = dUTP + NH3 - 3.5.4.13 dCTP + H2O = dUTP + NH3 mechanism of bifunctional enzyme activity and feedback inhibition by dTTP 3.5.4.13 dCTP + H2O = dUTP + NH3 reaction involves S111, A124, E138 and two water molecules 3.5.4.13 dCTP + H2O = dUTP + NH3 the mechanism for the deamination of dCTP involves the four residues Ser102, Arg106, Ala115 and Glu129, structure-function relationship of the bifunctional enzyme, overview