3GVQ:
reference: Substrate shuttling between active sites of uroporphyrinogen decarboxylase is not required to generate coproporphyrinogen., Phillips JD, Warby CA, Whitby FG, Kushner JP, Hill CP, J Mol Biol. 2009 Jun 5;389(2):306-14. Epub 2009 Apr 10. PMID: 19362562

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