1CYO:
reference: Refinement and structural analysis of bovine cytochrome b5 at 1.5 A resolution., Durley RC, Mathews FS, Acta Crystallogr D Biol Crystallogr. 1996 Jan 1;52(Pt 1):65-76. PMID: 15299727

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