1KQD:
reference: Structures of nitroreductase in three states: effects of inhibitor binding and reduction., Haynes CA, Koder RL, Miller AF, Rodgers DW, J Biol Chem 2002 Mar 29;277(13):11513-20. PMID: 11805110

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