sons made to the human rhinovirus (HRV) 3Cpro.28 Although these two proteases share very little sequence conservation, the substrate consensus sequences have a Gln residue in common at P1. Analysis of the HRV 3Cpro crystal structure with 1 (rupintrivir; Figure 2) revealed binding interactions that are like those observed for 1 bound to TGEV 3CLpro, which was used in the construction of