1RGQ:
reference: Hepatitis C NS3 protease inhibition by peptidyl-alpha-ketoamide inhibitors: kinetic mechanism and structure., Liu Y, Stoll VS, Richardson PL, Saldivar A, Klaus JL, Molla A, Kohlbrenner W, Kati WM, Arch Biochem Biophys 2004 Jan 15;421(2):207-16. PMID: 14984200

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