6IXD:
reference: Acquired Removability of Aspartic Protease Inhibitors by Direct Biotinylation., Hidaka K, Adachi M, Tsuda Y, Bioconjug Chem. 2019 Apr 22. doi: 10.1021/acs.bioconjchem.9b00195. PMID: 30990716

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