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bioRxiv · 10.1101/2021.05.03.442392

The method utilized to purify the SARS-CoV-2 N protein can affect its molecular properties

Tarczewska, A.·Kolonko-Adamska, M.·Zarebski, M.·Dobrucki, J. W.·Ozyhar, A.·Greb-Markiewicz, B.
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Abstract

One of the main structural proteins of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the nucleocapsid protein (N). The basic function of this protein is to bind genomic RNA and to form a protective nucleocapsid in the mature virion. The intrinsic ability of the N protein to interact with nucleic acids makes its purification very challenging. Therefore, typically employed purification methods appear to be insufficient for removing nucleic acid contamination. In this study, we present a novel purification protocol that enables the N protein to be prepared without any bound nucleic acids. We also performed comparative structural analysis of the N protein contaminated with nucleic acids and free of contamination and showed significant differences in the structural and phase separation properties of the protein. These results indicate that nucleic-acid contamination may severely affect molecular properties of the purified N protein. In addition, the notable ability of the N protein to form condensates whose morphology and behaviour suggest more ordered forms resembling gel-like or solid structures is described.

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Tarczewska, A., Kolonko-Adamska, M., Zarebski, M., Dobrucki, J. W., Ozyhar, A., Greb-Markiewicz, B.. 2021-05-04. The method utilized to purify the SARS-CoV-2 N protein can affect its molecular properties. https://doi.org/10.1101/2021.05.03.442392

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