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.>DOI:
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机译：正链RNA病毒是病毒的最大遗传类别，包括许多重要的病原体，例如寨卡病毒。这些病毒在新型的，膜结合的微型细胞器中复制其RNA基因组，但是在这些隔室中病毒蛋白和RNA的组织在很大程度上是未知的。我们使用了冷冻电子断层扫描来揭示Flock house nodavirus（FHV）RNA复制区室的许多先前无法识别的特征。线粒体外膜的这些球形内陷充满了电子致密的RNA原纤维，它们的体积与RNA复制模板的长度紧密相关。每个球体的颈孔都被一个醒目的杯状环形结构冠冕，该环形结构包含多功能FHV RNA复制蛋白A。这些子冠的子图平均显示十二倍的对称性，同心的侧翼突起和中心电子密度。许多冠与长的细胞质原纤维相关，可能是后代RNA输出。这些结果为正链RNA病毒复制区室的结构，组装，功能和控制提供了新的机械原理。> DOI：
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