Cytidine deaminase zinc-binding domain. These enzymes are Zn dependent. The zinc ion in the active site plays a central role in the proposed catalytic mechanism, activating a water molecule to form a hydroxide ion that performs a nucleophilic attack on the substrate. Cytidine deaminases catalyze the deamination of cytidine to uridine and are important in the pyrimadine salvage pathway in many cell types, from bacteria to humans. This family also includes the apoBec proteins, which are a mammal specific expansion of RNA editing enzymes, and the closely related phorbolins, and the AID (activation-induced) enzymes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",