6FMO:
reference: Binding of a physiological substrate causes large-scale conformational reorganization in cytochrome P450 51., Hargrove TY, Wawrzak Z, Fisher PM, Child SA, Nes WD, Guengerich FP, Waterman MR, Lepesheva GI, J Biol Chem. 2018 Oct 16. pii: RA118.005850. doi: 10.1074/jbc.RA118.005850. PMID: 30327430

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