3TKW:
reference: Terminal interface conformations modulate dimer stability prior to amino terminal autoprocessing of HIV-1 protease., Agniswamy J, Sayer JM, Weber IT, Louis JM, Biochemistry. 2012 Feb 7;51(5):1041-50. Epub 2012 Jan 24. PMID: 22242794

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