2VJY:
reference: Covalently bound substrate at the regulatory site of yeast pyruvate decarboxylases triggers allosteric enzyme activation., Kutter S, Weiss MS, Wille G, Golbik R, Spinka M, Konig S, J Biol Chem. 2009 Feb 26. PMID: 19246454

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