1DBT:
reference: The crystal structure and mechanism of orotidine 5'-monophosphate decarboxylase., Appleby TC, Kinsland C, Begley TP, Ealick SE, Proc Natl Acad Sci U S A 2000 Feb 29;97(5):2005-10. PMID: 10681442

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