Assembly and cryo-EM structures of RNA-specific measles virus nucleocapsids provide mechanistic insight into paramyxoviral replication - Groupe Dynamique et Cinétique des processus moléculaires / Dynamics and Kinetics of Molecular Processes Group (IBS-DYNAMOP) Accéder directement au contenu
Article Dans Une Revue Proceedings of the National Academy of Sciences of the United States of America Année : 2019

Assembly and cryo-EM structures of RNA-specific measles virus nucleocapsids provide mechanistic insight into paramyxoviral replication

Ambroise Desfosses
Sigrid Milles
Serafima Guseva
Damien Maurin
  • Fonction : Auteur
  • PersonId : 963118
Guy Schoehn
Irina Gutsche
Martin Blackledge

Résumé

Assembly of paramyxoviral nucleocapsids on the RNA genome is an essential step in the viral cycle. The structural basis of this process has remained obscure due to the inability to control encapsidation. We used a recently developed approach to assemble measles virus nucleocapsid-like particles on specific sequences of RNA hexamers (poly-Adenine and viral genomic 5') in vitro, and determined their cryoelectron microscopy maps to 3.3-Å resolution. The structures unambiguously determine 5' and 3' binding sites and thereby the binding-register of viral genomic RNA within nucleocapsids. This observation reveals that the 3' end of the genome is largely exposed in fully assembled measles nucleocapsids. In particular, the final three nucleotides of the genome are rendered accessible to the RNA-dependent RNA polymerase complex, possibly enabling efficient RNA processing. The structures also reveal local and global conformational changes in the nucleoprotein upon assembly, in particular involving helix α6 and helix α13 that form edges of the RNA binding groove. Disorder is observed in the bound RNA, localized at one of the two backbone conformational switch sites. The high-resolution structure allowed us to identify putative nucleobase interaction sites in the RNA-binding groove, whose impact on assembly kinetics was measured using real-time NMR. Mutation of one of these sites, R195, whose sidechain stabilizes both backbone and base of a bound nucleic acid, is thereby shown to be essential for nucleocapsid-like particle assembly.
Fichier principal
Vignette du fichier
desfosses2019.pdf (2.85 Mo) Télécharger le fichier
Origine : Accord explicite pour ce dépôt

Dates et versions

hal-02070475 , version 1 (21-11-2020)

Identifiants

Citer

Ambroise Desfosses, Sigrid Milles, Malene Ringkjøbing Jensen, Serafima Guseva, Jacques-Philippe Colletier, et al.. Assembly and cryo-EM structures of RNA-specific measles virus nucleocapsids provide mechanistic insight into paramyxoviral replication. Proceedings of the National Academy of Sciences of the United States of America, 2019, 116 (10), pp.4256-4264. ⟨10.1073/pnas.1816417116⟩. ⟨hal-02070475⟩
184 Consultations
34 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More