Institut Pasteur, Département de Virologie, Unité de Virologie Structurale, F-75724 Paris Cedex 15, France.
Cell Microbiol. 2011 Oct;13(10):1451-9. doi: 10.1111/j.1462-5822.2011.01653.x. Epub 2011 Aug 11.
A number of viruses transport their genomic material from cell to cell enclosed within a lipid bilayer that is in turn encased within a symmetric protein shell. This review focuses in a group of RNA viruses that have this type of virions. This group includes several of important human pathogenic viruses, such as the hepatitis C virus, dengue virus, chikungunya virus, rubella virus and the bunyaviruses. The best studied are the flaviviruses and the alphaviruses, which have a β-sheet rich class II viral fusion protein used for entry into susceptible cells. We extend here the class II concept to encompass symmetric viruses in which the envelope proteins are derived from a precursor polyprotein containing two transmembrane glycoproteins arranged in tandem. The first glycoprotein acts as chaperone for the folding of the second one, which carries the membrane fusion function. Since the bunyaviruses, included here, are very similar to the class I arenaviruses in other respects, this analysis highlights the patchwork nature of the various viral functional modules acting at different stages of the virus cycle, which appear assembled from genes of different origins.
许多病毒将其基因组物质包裹在脂质双层内，从一个细胞运输到另一个细胞，而脂质双层反过来又被包裹在对称的蛋白质壳内。本综述集中讨论了具有这种类型病毒粒子的一组 RNA 病毒。这组病毒包括几种重要的人类致病病毒，如丙型肝炎病毒、登革热病毒、基孔肯雅热病毒、风疹病毒和布尼亚病毒。研究得最好的是黄病毒和甲病毒，它们具有富含β-片层的 II 类病毒融合蛋白，用于进入易感细胞。我们在这里扩展了 II 类概念，以包含对称病毒，其中包膜蛋白来自含有两个串联排列的跨膜糖蛋白的前体多蛋白。第一个糖蛋白作为第二个糖蛋白折叠的伴侣，第二个糖蛋白携带膜融合功能。由于包括在这里的布尼亚病毒在其他方面与 I 类沙粒病毒非常相似，因此这种分析突出了各种病毒功能模块在病毒周期的不同阶段的拼凑性质，这些模块似乎是由不同来源的基因组装而成的。
