5XDH:
reference: Anammox Organism KSU-1 Expresses a Novel His/DOPA Ligated Cytochrome c., Hira D, Kitamura R, Nakamura T, Yamagata Y, Furukawa K, Fujii T, J Mol Biol. 2018 Apr 13;430(8):1189-1200. doi: 10.1016/j.jmb.2018.02.017. Epub, 2018 Feb 23. PMID: 29481839

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