5VKV:
reference: Solution structure and elevator mechanism of the membrane electron transporter CcdA., Zhou Y, Bushweller JH, Nat Struct Mol Biol. 2018 Feb;25(2):163-169. doi: 10.1038/s41594-018-0022-z. Epub, 2018 Jan 29. PMID: 29379172

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