1OZK:
reference: Functional properties of the alternative NADH:ubiquinone oxidoreductase from E. coli through comparative 3-D modelling., Schmid R, Gerloff DL, FEBS Lett. 2004 Dec 3;578(1-2):163-8. PMID: 15581635

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