2ISQ:
reference: Structural basis for interaction of o-acetylserine sulfhydrylase and serine acetyltransferase in the Arabidopsis cysteine synthase complex., Francois JA, Kumaran S, Jez JM, Plant Cell. 2006 Dec;18(12):3647-55. Epub 2006 Dec 28. PMID: 17194764

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