Cryo-electron tomography reveals novel features of a viral RNA replication compartment

eLife

Desirée Benefield¹  Marisa S Otegui¹  Janice G Pennington²  Mark Horswill³  Daniel Castaño-Diez⁴  Johan A den Boon⁴  Paul Ahlquist⁴  Kenneth J Ertel⁴ 

[1] Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States;Morgridge Institute for Research, University of Wisconsin-Madison, Madison, United States;BioEM lab, Biozentrum, University of Basel, Basel, Switzerland;Institute for Molecular Virology, University of Wisconsin-Madison, Madison, United States;

关键词: flock house virus;    RNA virus replication;    mitochondrion;    cryo-EM;    tomography;   

DOI  :  10.7554/eLife.25940

来源: DOAJ

【 摘 要 】

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 has been 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.

【 授权许可】

Unknown