1KM5:
reference: Mapping the active site-ligand interactions of orotidine 5'-monophosphate decarboxylase by crystallography., Wu N, Gillon W, Pai EF, Biochemistry 2002 Mar 26;41(12):4002-11. PMID: 11900543

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