Structural basis for translational shutdown and immune evasion by the Nsp1 protein of SARS-CoV-2.
Thoms, M., Buschauer, R., Ameismeier, M., Koepke, L., Denk, T., Hirschenberger, M., Kratzat, H., Hayn, M., Mackens-Kiani, T., Cheng, J., Straub, J.H., Sturzel, C.M., Frohlich, T., Berninghausen, O., Becker, T., Kirchhoff, F., Sparrer, K.M.J., Beckmann, R.(2020) Science 369: 1249-1255
- PubMed: 32680882 
- DOI: https://doi.org/10.1126/science.abc8665
- Primary Citation of Related Structures:  
6ZLW, 6ZM7, 6ZME, 6ZMI, 6ZMO, 6ZMT, 6ZN5, 6ZON, 6ZP4 - PubMed Abstract: 
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current coronavirus disease 2019 (COVID-19) pandemic. A major virulence factor of SARS-CoVs is the nonstructural protein 1 (Nsp1), which suppresses host gene expression by ribosome association. Here, we show that Nsp1 from SARS-CoV-2 binds to the 40 S ribosomal subunit, resulting in shutdown of messenger RNA (mRNA) translation both in vitro and in cells. Structural analysis by cryo-electron microscopy of in vitro-reconstituted Nsp1-40 S and various native Nsp1-40 S and -80 S complexes revealed that the Nsp1 C terminus binds to and obstructs the mRNA entry tunnel. Thereby, Nsp1 effectively blocks retinoic acid-inducible gene I-dependent innate immune responses that would otherwise facilitate clearance of the infection. Thus, the structural characterization of the inhibitory mechanism of Nsp1 may aid structure-based drug design against SARS-CoV-2.
Organizational Affiliation: 
Gene Center Munich, Department of Biochemistry, University of Munich, Munich, Germany.