4GAC:
reference: High-resolution structure of AKR1a4 in the apo form and its interaction with ligands., Faucher F, Jia Z, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 Nov 1;68(Pt 11):1271-4., doi: 10.1107/S1744309112037128. Epub 2012 Oct 26. PMID: 23143230

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