4TSK:
reference: Uncovering rare NADH-preferring ketol-acid reductoisomerases., Brinkmann-Chen S, Cahn JK, Arnold FH, Metab Eng. 2014 Aug 27;26C:17-22. doi: 10.1016/j.ymben.2014.08.003. PMID: 25172159

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