In enzymology, a dCTP deaminase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are dCTP and H<sub>2</sub>O, whereas its two products are dUTP and NH<sub>3</sub>.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is dCTP aminohydrolase. Other names in common use include deoxycytidine triphosphate deaminase, and 5-methyl-dCTP deaminase. This enzyme participates in pyrimidine metabolism.
As of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , and .