2OA1:
reference: The structure of flavin-dependent tryptophan 7-halogenase RebH., Bitto E, Huang Y, Bingman CA, Singh S, Thorson JS, Phillips GN Jr, Proteins. 2008 Jan 1;70(1):289-93. PMID: 17876823

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