4OBU:
reference: Discovery and Characterization of Gut Microbiota Decarboxylases that Can Produce the Neurotransmitter Tryptamine., Williams BB, Van Benschoten AH, Cimermancic P, Donia MS, Zimmermann M, Taketani M, Ishihara A, Kashyap PC, Fraser JS, Fischbach MA, Cell Host Microbe. 2014 Oct 8;16(4):495-503. doi: 10.1016/j.chom.2014.09.001., Epub 2014 Sep 25. PMID: 25263219

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