Fig. 1.

Structure of the inhibitors bound to M^proactive site. (A) Chemical structures of rupintrivir and AG7404. Asterisks indicate the carbon atoms that form irreversible covalent bonds with SARS-CoV-2 M^pro Cys145. (B) SARS-CoV-2 M^pro with rupintrivir. (C) SARS-CoV-2 M^pro with AG7404. (D) SARS-CoV-1 M^pro with AG7404. SARS-CoV-2 M^pro is shown in gray, SARS-CoV-1 M^pro in wheat, rupintrivir in orange and AG7404 in lime green. Proteins are shown as atom-colored surface, with atomic detail of the protein residues interacting with the compounds. Hydrogen bonds are marked with discontinuous dark green lines. Subsites from P4 to P1′ are also labeled.