InterPro domain: IPR013171

This region contains the zinc-binding domain of cytidine and deoxycytidylate deaminase.

Cytidine deaminase ( 3.5.4.5 ) (cytidine aminohydrolase) catalyzes the hydrolysis of cytidine into uridine and ammonia while deoxycytidylate deaminase ( 3.5.4.12 ) (dCMP deaminase) hydrolyzes dCMP into dUMP. Both enzymes are known to bind zinc and to require it for their catalytic activity [ 1 , 2 ]. These two enzymes do not share any sequence similarity with the exception of a region that contains three conserved histidine and cysteine residues which are thought to be involved in the binding of the catalytic zinc ion.

1. Cloning and nucleotide sequence of the Escherichia coli cytidine deaminase (ccd) gene. Biochemistry 31, 4168-74
2. T4-phage deoxycytidylate deaminase is a metalloprotein containing two zinc atoms per subunit. J. Biol. Chem. 268, 2288-91