Fig. 4. The substrate envelope of SARS-CoV-2 Mpro.
a The substrates bound at the Mpro active site are depicted as sticks in the superimposed cocrystal structures, where the protease is in gray surface representation. The consensus volume occupied by the substrates define the substrate envelope, shown as the blue volume and is the intersection of any four of the nine substrates. b The gradient substrate envelope colored according to the number of substrates that occupy the consensus volume. Purple to red gradient indicates less to more consensus. c Substrate nsp8-nsp9 in the substrate envelope. d Superposition of cocrystal structures with cleaved N-terminal product complexes, defining the product envelope (blue volume).