1YBH:
reference: Herbicide-binding sites revealed in the structure of plant acetohydroxyacid synthase., McCourt JA, Pang SS, King-Scott J, Guddat LW, Duggleby RG, Proc Natl Acad Sci U S A. 2006 Jan 17;103(3):569-73. Epub 2006 Jan 10. PMID: 16407096

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