5W6K:
reference: Snapshots of an evolved DNA polymerase pre- and post-incorporation of an unnatural nucleotide., Singh I, Laos R, Hoshika S, Benner SA, Georgiadis MM, Nucleic Acids Res. 2018 Jul 9. pii: 5050621. doi: 10.1093/nar/gky552. PMID: 29986111

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