1SB3:
reference: Structure of a Xanthine Oxidase-Related 4-Hydroxybenzoyl-CoA Reductase with an Additional [4Fe-4S] Cluster and an Inverted Electron Flow., Unciuleac M, Warkentin E, Page CC, Boll M, Ermler U, Structure (Camb) 2004 Dec;12(12):2249-56. PMID: 15576037

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