1NSO:
reference: Three-dimensional structure of a monomeric form of a retroviral protease., Veverka V, Bauerova H, Zabransky A, Lang J, Ruml T, Pichova I, Hrabal R, J Mol Biol 2003 Oct 31;333(4):771-80. PMID: 14568536

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