Catalyzes the deamination of dCTP to dUTP. dCTP + H(+) + H2O = dUTP + NH4(+) Inhibited by dTTP, which binds to the active site and stabilizes the inactive form of the enzyme (PubMed:17651436). Inhibited by inorganic phosphate (PubMed:15539408). kcat is 1.24 sec(-1). Pyrimidine metabolism; dUMP biosynthesis; dUMP from dCTP (dUTP route): step 1/2. Homotrimer. Mutant accumulates dCTP. Belongs to the dCTP deaminase family.