3E9Y:
reference: Crystal structures of two novel sulfonylurea herbicides in complex with Arabidopsis thaliana acetohydroxyacid synthase., Wang JG, Lee PK, Dong YH, Pang SS, Duggleby RG, Li ZM, Guddat LW, FEBS J. 2009 Mar;276(5):1282-90. PMID: 19187232

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