Fig. 3: Comparison of room-temperature and low-temperature structures.

a A superposition of our room temperature ligand-free structure of 3CL Mpro (magenta) with the ligand-free structure of 3CL Mpro (PDB ID 6Y2E) obtained at 100 K (cyan). b Residues 192–198 in the P5 binding pocket differ in conformation between the room temperature and 100 K structures.