FIGURE 1.

Scheme of fragment ‐based drug design of B19. (A) Three selected drug‐fragments: JFM, U0P, and HWH. For each of three fragment drugs, the head, and tail parts are on the left and right sides, respectively. (B) The crystal structure of JFM in the ligand‐binding pocket of Mpro (PDB ID: 5R7Y). (C) The crystal structure of U0P in the ligand‐binding pocket of Mpro (PDB ID: 5RGI). (D) The crystal structure of HWH in the ligand‐binding pocket of Mpro (PDB ID: 5R7Z). A DMSO molecule was co‐crystallized inside the subsite S1. (E) The assembly of JFM, U0P, and HWH into B19 with a linker (shaded)