1IZD:
reference: Crystal structures of Aspergillus oryzae aspartic proteinase and its complex with an inhibitor pepstatin at 1.9A resolution., Kamitori S, Ohtaki A, Ino H, Takeuchi M, J Mol Biol 2003 Mar 7;326(5):1503-11. PMID: 12595261

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