4WMD:
reference: Structures of the Middle East respiratory syndrome coronavirus 3C-like protease reveal insights into substrate specificity., Needle D, Lountos GT, Waugh DS, Acta Crystallogr D Biol Crystallogr. 2015 May;71(Pt 5):1102-11. doi:, 10.1107/S1399004715003521. Epub 2015 Apr 24. PMID: 25945576

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