This gene is a member of the
cytidine deaminase gene family. It is one of seven related genes or
pseudogenes found in a
cluster thought to result from
gene duplication, on
chromosome 22. Members of the cluster encode proteins that are structurally and functionally related to the C to U RNA-editing cytidine deaminase
APOBEC1. Conversely, A3 proteins enzymatically convert cytidine to uridine present in the single stranded DNA. Two residues in loop 1 of A3C were demonstrated to determine its antiviral activity against HIV-1. == Structure ==