3KP9:
reference: Structure of a bacterial homologue of vitamin K epoxide reductase., Li W, Schulman S, Dutton RJ, Boyd D, Beckwith J, Rapoport TA, Nature. 2010 Jan 28;463(7280):507-12. PMID: 20110994

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