Genome-regulated Assembly of a ssRNA Virus May Also Prepare It for Infection. (original) (raw)
Chandler-Bostock, R orcid.org/0000-0002-1225-4601, Bingham, RJ, Clark, S et al. (10 more authors) (2022)Genome-regulated Assembly of a ssRNA Virus May Also Prepare It for Infection. Journal of Molecular Biology, 434 (20). 167797. 167797-. ISSN 0022-2836
Abstract
Many single-stranded, positive-sense RNA viruses regulate assembly of their infectious virions by forming multiple, cognate coat protein (CP)-genome contacts at sites termed Packaging Signals (PSs). We have determined the secondary structures of the bacteriophage MS2 ssRNA genome (gRNA) frozen in defined states using constraints from X-ray synchrotron footprinting (XRF). Comparison of the footprints from phage and transcript confirms the presence of multiple PSs in contact with CP dimers in the former. This is also true for a virus-like particle (VLP) assembled around the gRNA in vitro in the absence of the single-copy Maturation Protein (MP) found in phage. Since PS folds are present at many sites across gRNA transcripts, it appears that this genome has evolved to facilitate this mechanism of assembly regulation. There are striking differences between the gRNA-CP contacts seen in phage and the VLP, suggesting that the latter are inappropriate surrogates for aspects of phage structure/function. Roughly 50% of potential PS sites in the gRNA are not in contact with the protein shell of phage. However, many of these sit adjacent to, albeit not in contact with, PS-binding sites on CP dimers. We hypothesize that these act as PSs transiently during assembly but subsequently dissociate. Combining the XRF data with PS locations from an asymmetric cryo-EM reconstruction suggests that the genome positions of such dissociations are non-random and may facilitate infection. The loss of many PS-CP interactions towards the 3′ end of the gRNA would allow this part of the genome to transit more easily through the narrow basal body of the pilus extruding machinery. This is the known first step in phage infection. In addition, each PS-CP dissociation event leaves the protein partner trapped in a non-lowest free-energy conformation. This destabilizes the protein shell which must disassemble during infection, further facilitating this stage of the life-cycle.
Metadata
| Authors/Creators: | Chandler-Bostock, R  https://orcid.org/0000-0002-1225-4601Bingham, RJClark, SScott, AJP https://orcid.org/0000-0002-7989-2675Wroblewski, EBarker, AWhite, SJDykeman, ECMata, CPBohon, JFarquhar, ETwarock, RStockley, PG https://orcid.org/0000-0002-1360-2751 |
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| Copyright, Publisher and Additional Information: | © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | RNA PS-mediated virion assembly; bacteriophage MS2; RNA X-ray footprinting; molecular frustration; phage infection |
| Dates: | Accepted: 15 August 2022Published (online): 20 August 2022Published: 30 October 2022 |
| Institution: | The University of Leeds |
| Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > Biological Chemistry (Leeds)The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > Molecular Virology (Leeds) |
| Depositing User: | Symplectic Publications |
| Date Deposited: | 27 Sep 2022 11:31 |
| Last Modified: | 27 Sep 2022 11:31 |
| Status: | Published |
| Publisher: | Elsevier |
| Identification Number: | https://doi.org/10.1016/j.jmb.2022.167797 |
| Related URLs: | PubMed URL |