1LVO:
reference: Structure of coronavirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-helical domain., Anand K, Palm GJ, Mesters JR, Siddell SG, Ziebuhr J, Hilgenfeld R, EMBO J 2002 Jul 1;21(13):3213-24. PMID: 12093723

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