Assembly of SARS-CoV-2 nucleocapsid protein with nucleic acid.
Nucleic Acids Res
; 52(11): 6647-6661, 2024 Jun 24.
Article
en En
| MEDLINE
| ID: mdl-38587193
ABSTRACT
The viral genome of SARS-CoV-2 is packaged by the nucleocapsid (N-)protein into ribonucleoprotein particles (RNPs), 38 ± 10 of which are contained in each virion. Their architecture has remained unclear due to the pleomorphism of RNPs, the high flexibility of N-protein intrinsically disordered regions, and highly multivalent interactions between viral RNA and N-protein binding sites in both N-terminal (NTD) and C-terminal domain (CTD). Here we explore critical interaction motifs of RNPs by applying a combination of biophysical techniques to ancestral and mutant proteins binding different nucleic acids in an in vitro assay for RNP formation, and by examining nucleocapsid protein variants in a viral assembly assay. We find that nucleic acid-bound N-protein dimers oligomerize via a recently described protein-protein interface presented by a transient helix in its long disordered linker region between NTD and CTD. The resulting hexameric complexes are stabilized by multivalent protein-nucleic acid interactions that establish crosslinks between dimeric subunits. Assemblies are stabilized by the dimeric CTD of N-protein offering more than one binding site for stem-loop RNA. Our study suggests a model for RNP assembly where N-protein scaffolding at high density on viral RNA is followed by cooperative multimerization through protein-protein interactions in the disordered linker.
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Base de datos:
MEDLINE
Asunto principal:
ARN Viral
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Multimerización de Proteína
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Proteínas de la Nucleocápside de Coronavirus
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SARS-CoV-2
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2024
Tipo del documento:
Article