4HKP:
reference: Novel cytidine-based orotidine-5'-monophosphate decarboxylase inhibitors with an unusual twist., Purohit MK, Poduch E, Wei LW, Crandall IE, To T, Kain KC, Pai EF, Kotra LP, J Med Chem. 2012 Nov 26;55(22):9988-97. doi: 10.1021/jm301176r. Epub 2012 Oct 18. PMID: 22991951

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