High-resolution structure and biophysical characterization of the nucleocapsid phosphoprotein dimerization domain from the Covid-19 severe acute respiratory syndrome coronavirus 2.Zinzula, L., Basquin, J., Bohn, S., Beck, F., Klumpe, S., Pfeifer, G., Nagy, I., Bracher, A., Hartl, F.U., Baumeister, W.
(2021) Biochem Biophys Res Commun 538: 54-62
- PubMed: 33039147
- DOI: https://doi.org/10.1016/j.bbrc.2020.09.131
- Primary Citation of Related Structures:
- PubMed Abstract:
Unprecedented by number of casualties and socio-economic burden occurring worldwide, the coronavirus disease 2019 (Covid-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the worst health crisis of this century. In order to develop adequate countermeasures against Covid-19, identification and structural characterization of suitable antiviral targets within the SARS-CoV-2 protein repertoire is urgently needed. The nucleocapsid phosphoprotein (N) is a multifunctional and highly immunogenic determinant of virulence and pathogenicity, whose main functions consist in oligomerizing and packaging the single-stranded RNA (ssRNA) viral genome. Here we report the structural and biophysical characterization of the SARS-CoV-2 N C-terminal domain (CTD), on which both N homo-oligomerization and ssRNA binding depend. Crystal structures solved at 1.44 Å and 1.36 Å resolution describe a rhombus-shape N CTD dimer, which stably exists in solution as validated by size-exclusion chromatography coupled to multi-angle light scattering and analytical ultracentrifugation. Differential scanning fluorimetry revealed moderate thermal stability and a tendency towards conformational change. Microscale thermophoresis demonstrated binding to a 7-bp SARS-CoV-2 genomic ssRNA fragment at micromolar affinity. Furthermore, a low-resolution preliminary model of the full-length SARS-CoV N in complex with ssRNA, obtained by cryo-electron microscopy, provides an initial understanding of self-associating and RNA binding functions exerted by the SARS-CoV-2 N.
The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152, Martinsried, Germany; The Max-Planck Institute of Biochemistry, Department of Cellular Machines and Signaling, Am Klopferspitz 18, 82152, Martinsried, Germany.