Mechanisms of assembly and genome packaging in an RNA virus revealed by high-resolution cryo-EM.
Mechanisms of assembly and genome packaging in an RNA virus revealed by high-resolution cryo-EM.
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DOI：
10.1038/ncomms10113
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发表时间：
2015-12-10
影响因子：
16.6
通讯作者：
Ranson NA
中科院分区：
文献类型：
--
作者：
Hesketh EL;Meshcheriakova Y;Dent KC;Saxena P;Thompson RF;Cockburn JJ;Lomonossoff GP;Ranson NA
豇豆花叶病毒是小核糖核酸病毒目的一种侵染植物的病毒，在生物技术应用的发展中具有重要意义。尽管小核糖核酸病毒目衣壳的晶体结构超过100种，但对衣壳组装和基因组组装的机制知之甚少。在这里，我们已经确定了野生型病毒和空病毒样颗粒的冷冻电子显微镜重建，分别为3.4 μ m和3.0 μ m的分辨率，并建立了从头原子模型的衣壳。这些新结构揭示了小外壳蛋白亚基的C-末端区域，这是病毒组装所必需的，并且在先前确定的晶体结构中缺失，以及与病毒基因组结合的残基。这些观察使我们能够开发一种新的基因组衣壳化和衣壳组装模型。 很少有人知道如何植物感染豇豆花叶病毒（CPMV）-一个宝贵的工具，在几个生物技术应用-包装其单链RNA基因组到衣壳。在这里，作者提出了两个高分辨率的冷冻电镜结构的CPMV和一个新的模型的RNA识别和衣壳组装。
Cowpea mosaic virus is a plant-infecting member of the Picornavirales and is of major interest in the development of biotechnology applications. Despite the availability of >100 crystal structures of Picornavirales capsids, relatively little is known about the mechanisms of capsid assembly and genome encapsidation. Here we have determined cryo-electron microscopy reconstructions for the wild-type virus and an empty virus-like particle, to 3.4 Å and 3.0 Å resolution, respectively, and built de novo atomic models of their capsids. These new structures reveal the C-terminal region of the small coat protein subunit, which is essential for virus assembly and which was missing from previously determined crystal structures, as well as residues that bind to the viral genome. These observations allow us to develop a new model for genome encapsidation and capsid assembly. Little is known about how the plant-infecting cowpea mosaic virus (CPMV)—an invaluable tool in several biotechnology applications—packages its single-strand RNA genome into the capsid. Here the authors present two high-resolution cryo-EM structures of CPMV and a new model for RNA recognition and capsid assembly.