3TK3:
reference: Investigation by site-directed mutagenesis of the role of cytochrome P450 2B4 non-active site residues in protein-ligand interactions based on crystal structures of the ligand-bound enzyme., Wilderman PR, Gay SC, Jang HH, Zhang Q, Stout CD, Halpert JR, FEBS J. 2011 Nov 3. doi: 10.1111/j.1742-4658.2011.08411.x. PMID: 22051155

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