4LBT:
reference: Structure-based design of inhibitors of the aspartic protease endothiapepsin by exploiting dynamic combinatorial chemistry., Mondal M, Radeva N, Koster H, Park A, Potamitis C, Zervou M, Klebe G, Hirsch AK, Angew Chem Int Ed Engl. 2014 Mar 17;53(12):3259-63. doi: 10.1002/anie.201309682. , Epub 2014 Feb 14. PMID: 24532096

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