4HVP:
reference: Structure of complex of synthetic HIV-1 protease with a substrate-based inhibitor at 2.3 A resolution., Miller M, Schneider J, Sathyanarayana BK, Toth MV, Marshall GR, Clawson L, Selk L, Kent SB, Wlodawer A, Science 1989 Dec 1;246(4934):1149-52. PMID: 2686029

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