5CQK:
reference: Crystal Structure of the DNA Deaminase APOBEC3B Catalytic Domain., Shi K, Carpenter MA, Kurahashi K, Harris RS, Aihara H, J Biol Chem. 2015 Sep 28. pii: jbc.M115.679951. PMID: 26416889

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).