1D6S:
reference: Ligand binding induces a large conformational change in O-acetylserine sulfhydrylase from Salmonella typhimurium., Burkhard P, Tai CH, Ristroph CM, Cook PF, Jansonius JN, J Mol Biol 1999 Aug 27;291(4):941-53. PMID: 10452898

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