Fig. 1.

Crystal structure of a typical 3C-like protease complexed with the inhibitor and the interaction mode (the structures in 1-3 are drawn based on the crystal structure PDB ID: 4YOI; the structures in 1 and 2 show a solvent accessible surface colored in silver; in the structure presented in 3, the green dashed lines indicate the H-bound, and the pink dashed line indicates the hydrophobic interactions; structures in 4 are drawn based on the crystal structure PDB ID: 1P9U, a hydrophobic surface is colored in blue).