4KQH:
reference: Dissecting cobamide diversity through structural and functional analyses of the base-activating CobT enzyme of Salmonella enterica., Chan CH, Newmister SA, Talyor K, Claas KR, Rayment I, Escalante-Semerena JC, Biochim Biophys Acta. 2014 Jan;1840(1):464-75. doi: 10.1016/j.bbagen.2013.09.038., Epub 2013 Oct 10. PMID: 24121107

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