Download MendeleyAssembly of infectious enteroviruses depends on multiple, conserved genomic RNA-coat protein contacts.
Chandler-Bostock, R., Mata, C.P., Bingham, R.J., Dykeman, E.C., Meng, B., Tuthill, T.J., Rowlands, D.J., Ranson, N.A., Twarock, R., Stockley, P.G.(2020) PLoS Pathog 16: e1009146-e1009146
- PubMed: 33370422
- DOI: https://doi.org/10.1371/journal.ppat.1009146
- Primary Citation of Related Structures:
6THD, 6THN - PubMed Abstract:
Picornaviruses are important viral pathogens, but despite extensive study, the assembly process of their infectious virions is still incompletely understood, preventing the development of anti-viral strategies targeting this essential part of the life cycle. We report the identification, via RNA SELEX and bioinformatics, of multiple RNA sites across the genome of a typical enterovirus, enterovirus-E (EV-E), that each have affinity for the cognate viral capsid protein (CP) capsomer. Many of these sites are evolutionarily conserved across known EV-E variants, suggesting they play essential functional roles. Cryo-electron microscopy was used to reconstruct the EV-E particle at ~2.2 Å resolution, revealing extensive density for the genomic RNA. Relaxing the imposed symmetry within the reconstructed particles reveals multiple RNA-CP contacts, a first for any picornavirus. Conservative mutagenesis of the individual RNA-contacting amino acid side chains in EV-E, many of which are conserved across the enterovirus family including poliovirus, is lethal but does not interfere with replication or translation. Anti-EV-E and anti-poliovirus aptamers share sequence similarities with sites distributed across the poliovirus genome. These data are consistent with the hypothesis that these RNA-CP contacts are RNA Packaging Signals (PSs) that play vital roles in assembly and suggest that the RNA PSs are evolutionarily conserved between pathogens within the family, augmenting the current protein-only assembly paradigm for this family of viruses.
Organizational Affiliation:
Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
