3MWS:
reference: Autocatalytic maturation, physical/chemical properties, and crystal structure of group N HIV-1 protease: relevance to drug resistance., Sayer JM, Agniswamy J, Weber IT, Louis JM, Protein Sci. 2010 Nov;19(11):2055-72. PMID: 20737578

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