6IPD:
reference: Human DNA Polymerase mu Can Use a Noncanonical Mechanism for Multiple Mn(2+)-Mediated Functions., Chang YK, Huang YP, Liu XX, Ko TP, Bessho Y, Kawano Y, Maestre-Reyna M, Wu WJ, Tsai MD, J Am Chem Soc. 2019 May 17. doi: 10.1021/jacs.9b01741. PMID: 31067051

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