Cryo-electron tomography reveals novel features of a viral RNA replication compartment
- Janelia Research Campus, Howard Hughes Medical Institute, United States
- University of Wisconsin-Madison, United States
- University of Basel, Switzerland
Abstract
Positive-strand RNA viruses, the largest genetic class of viruses, include numerous important pathogens such as Zika virus. These viruses replicate their RNA genomes in novel, membrane-bounded mini-organelles, but the organization of viral proteins and RNAs in these compartments is largely unknown. We used cryo-electron tomography to reveal many previously unrecognized features of Flock house nodavirus (FHV) RNA replication compartments. These spherular invaginations of outer mitochondrial membranes are packed with electron-dense RNA fibrils and their volumes are closely correlated with RNA replication template length. Each spherule's necked aperture is crowned by a striking cupped ring structure containing multifunctional FHV RNA replication protein A. Subtomogram averaging of these crowns revealed twelve-fold symmetry, concentric flanking protrusions, and a central electron density. Many crowns were associated with long cytoplasmic fibrils, likely to be exported progeny RNA. These results provide new mechanistic insights into positive-strand RNA virus replication compartment structure, assembly, function and control.
Article and author information
Author details
Funding
Howard Hughes Medical Institute (Investigator)
- Paul Ahlquist
Morgridge Institute for Research (Investigator)
- Paul Ahlquist
National Science Foundation (DBI 1126441)
- Marisa Otegui
- Paul Ahlquist
National Science Foundation (MCB 1614965)
- Marisa Otegui
Rowe Family Virology Venture Fund (Investigator)
- Paul Ahlquist
National Institutes of Health (T32 AI078985)
- Desirée Benefield
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Ertel et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Cryo-electron tomography reveals novel features of a viral RNA replication compartment
eLife 6:e25940.
https://doi.org/10.7554/eLife.25940
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