3QHC:
reference: Symerythrin structures at atomic resolution and the origins of rubrerythrins and the ferritin-like superfamily., Cooley RB, Arp DJ, Karplus PA, J Mol Biol. 2011 Oct 14;413(1):177-94. Epub 2011 Aug 19. PMID: 21872605

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