6HV2:
reference: Drug design inspired by Nature: Crystallographic detection of auto-tailored protease inhibitor template., Gall FM, Hohl D, Frasson D, Wermelinger T, Mittl PRE, Sievers M, Riedl R, Angew Chem Int Ed Engl. 2019 Jan 7. doi: 10.1002/anie.201812348. PMID: 30615822

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