Structure-Based Stabilization of Non-native Protein-Protein Interactions of Coronavirus Nucleocapsid Proteins in Antiviral Drug Design.
Lin, S.M., Lin, S.C., Hsu, J.N., Chang, C.K., Chien, C.M., Wang, Y.S., Wu, H.Y., Jeng, U.S., Kehn-Hall, K., Hou, M.H.(2020) J Med Chem 63: 3131-3141
- PubMed: 32105468 
- DOI: https://doi.org/10.1021/acs.jmedchem.9b01913
- Primary Citation of Related Structures:  
6KL2, 6KL5, 6KL6 - PubMed Abstract: 
Structure-based stabilization of protein-protein interactions (PPIs) is a promising strategy for drug discovery. However, this approach has mainly focused on the stabilization of native PPIs, and non-native PPIs have received little consideration. Here, we identified a non-native interaction interface on the three-dimensional dimeric structure of the N-terminal domain of the MERS-CoV nucleocapsid protein (MERS-CoV N-NTD). The interface formed a conserved hydrophobic cavity suitable for targeted drug screening. By considering the hydrophobic complementarity during the virtual screening step, we identified 5-benzyloxygramine as a new N protein PPI orthosteric stabilizer that exhibits both antiviral and N-NTD protein-stabilizing activities. X-ray crystallography and small-angle X-ray scattering showed that 5-benzyloxygramine stabilizes the N-NTD dimers through simultaneous hydrophobic interactions with both partners, resulting in abnormal N protein oligomerization that was further confirmed in the cell. This unique approach based on the identification and stabilization of non-native PPIs of N protein could be applied toward drug discovery against CoV diseases.
Organizational Affiliation: 
Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 402, Taiwan.