3FR8:
reference: Conformational changes in a plant ketol-acid reductoisomerase upon Mg(2+) and NADPH binding as revealed by two crystal structures., Leung EW, Guddat LW, J Mol Biol. 2009 May 29;389(1):167-82. Epub 2009 Apr 9. PMID: 19362563

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