2CCB:
reference: Dodecins: a family of lumichrome binding proteins., Grininger M, Zeth K, Oesterhelt D, J Mol Biol. 2006 Mar 31;357(3):842-57. Epub 2006 Jan 18. PMID: 16460756

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