1Z42:
reference: The 1.3 A crystal structure of the flavoprotein YqjM reveals a novel class of Old Yellow Enzymes., Kitzing K, Fitzpatrick TB, Wilken C, Sawa J, Bourenkov GP, Macheroux P, Clausen T, J Biol Chem 2005 Jul 29;280(30):27904-13. Epub 2005 May 12. PMID: 15890652

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