1CMQ:
reference: Small molecule binding to an artificially created cavity at the active site of cytochrome c peroxidase., Fitzgerald MM, Churchill MJ, McRee DE, Goodin DB, Biochemistry 1994 Apr 5;33(13):3807-18. PMID: 8142383

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