3UCB:
reference: HIV-1 Protease with 20 Mutations Exhibits Extreme Resistance to Clinical Inhibitors through Coordinated Structural Rearrangements., Agniswamy J, Shen CH, Aniana A, Sayer JM, Louis JM, Weber IT, Biochemistry. 2012 Mar 20. PMID: 22404139

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