• PF-00835231 exhibits broad-spectrum inhibition against various coronaviral main proteases, including SARS-CoV-2, SARS-CoV, and MERS-CoV, as well as seven clinically relevant mutants.
• High-resolution crystal structures of Mpro-inhibitor complexes reveal key structural determinants and binding modes that explain the inhibitor's efficacy and adaptability.
• The structural insights provide a rational basis for designing next-generation antivirals with improved oral bioavailability and broad-spectrum activity against emerging coronaviruses.
• The study underscores the importance of targeting the highly conserved Mpro for developing therapeutic interventions against current and future coronavirus outbreaks.