3P3O:
reference: Structural Fine-Tuning of a Multifunctional Cytochrome P450 Monooxygenase., Zocher G, Richter ME, Mueller U, Hertweck C, J Am Chem Soc. 2011 Jan 31. PMID: 21280577

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