1PPP:
reference: Crystal structure of papain-E64-c complex. Binding diversity of E64-c to papain S2 and S3 subsites., Kim MJ, Yamamoto D, Matsumoto K, Inoue M, Ishida T, Mizuno H, Sumiya S, Kitamura K, Biochem J 1992 Nov 1;287 ( Pt 3):797-803. PMID: 1445241

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