1ICU:
reference: The structure of Escherichia coli nitroreductase complexed with nicotinic acid: three crystal forms at 1.7 A, 1.8 A and 2.4 A resolution., Lovering AL, Hyde EI, Searle PF, White SA, J Mol Biol 2001 May 25;309(1):203-13. PMID: 11491290

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