4HEA:
reference: Crystal structure of the entire respiratory complex I., Baradaran R, Berrisford JM, Minhas GS, Sazanov LA, Nature. 2013 Feb 28;494(7438):443-8. doi: 10.1038/nature11871. Epub 2013 Feb 17. PMID: 23417064

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