Crystal structure of APOBEC3A bound to single-stranded DNA reveals structural basis for cytidine deamination and specificity

Cytidine deaminases are evolutionarily conserved enzymes that edit genomes by deaminating cytidine to uridine. Here the authors present the crystal structure of APOBEC3A with a single-stranded DNA substrate bound in the active site to shed light on the mechanism and specificity of substrate recognition.