6CFW:
reference: Structure of an Ancient Respiratory System., Yu H, Wu CH, Schut GJ, Haja DK, Zhao G, Peters JW, Adams MWW, Li H, Cell. 2018 Apr 25. pii: S0092-8674(18)30403-3. doi: 10.1016/j.cell.2018.03.071. PMID: 29754813

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