3IQH:
reference: Design of O-acetylserine sulfhydrylase inhibitors by mimicking nature., Salsi E, Bayden AS, Spyrakis F, Amadasi A, Campanini B, Bettati S, Dodatko T, Cozzini P, Kellogg GE, Cook PF, Roderick SL, Mozzarelli A, J Med Chem. 2010 Jan 14;53(1):345-56. PMID: 19928859

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