This enzyme scavenges exogenous and endogenous cytidine and 2'-deoxycytidine for UMP synthesis. Functions as a conventional cytidine deaminase. Has no affinity for RNA and is not involved in RNA-editing by C-to-U deamination. cytidine + H(+) + H2O = NH4(+) + uridine 2'-deoxycytidine + H(+) + H2O = 2'-deoxyuridine + NH4(+) Binds 1 zinc ion per subunit. Inhibited by uridine, CMP and dCMP. Optimum pH is 7.5-8.0. Homodimer. Expressed in roots, rosette leaves, stems and flowers. Belongs to the cytidine and deoxycytidylate deaminase family. Sequencing errors.