4MFC:
reference: Metal-Dependent Conformational Activation Explains Highly Promutagenic Replication across O6-Methylguanine by Human DNA Polymerase beta, Koag MC, Lee S, J Am Chem Soc. 2014 Apr 2. PMID: 24694247

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