Structure of the HRV-C 3C-Rupintrivir Complex Provides New Insights for Inhibitor Design.
Yuan, S., Fan, K., Chen, Z., Sun, Y., Hou, H., Zhu, L.(2020) Virol Sin 35: 445-454
- PubMed: 32103448 
- DOI: https://doi.org/10.1007/s12250-020-00196-4
- Primary Citation of Related Structures:  
6KU7, 6KU8 - PubMed Abstract: 
Human rhinoviruses (HRVs) are the predominant infectious agents for the common cold worldwide. The HRV-C species cause severe illnesses in children and are closely related to acute exacerbations of asthma. 3C protease, a highly conserved enzyme, cleaves the viral polyprotein during replication and assists the virus in escaping the host immune system. These key roles make 3C protease an important drug target. A few structures of 3Cs complexed with an irreversible inhibitor rupintrivir have been determined. These structures shed light on the determinants of drug specificity. Here we describe the structures of HRV-C15 3C in free and inhibitor-bound forms. The volume-decreased S1' subsite and half-closed S2 subsite, which were thought to be unique features of enterovirus A 3C proteases, appear in the HRV-C 3C protease. Rupintrivir assumes an "intermediate" conformation in the complex, which might open up additional avenues for the design of potent antiviral inhibitors. Analysis of the features of the three-dimensional structures and the amino acid sequences of 3C proteases suggest new applications for existing drugs.
Organizational Affiliation: 
CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.