2VPW:
reference: Molecular mechanism of energy conservation in polysulfide respiration., Jormakka M, Yokoyama K, Yano T, Tamakoshi M, Akimoto S, Shimamura T, Curmi P, Iwata S, Nat Struct Mol Biol. 2008 Jul;15(7):730-7. Epub 2008 Jun 8. PMID: 18536726

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