Institut Pasteur, Department of Microbiology, 25 rue du Dr. Roux, Paris, 75015, France.
Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, 22908, USA.
Nat Commun. 2018 Aug 22;9(1):3360. doi: 10.1038/s41467-018-05684-6.
Different forms of viruses that infect archaea inhabiting extreme environments continue to be discovered at a surprising rate, suggesting that the current sampling of these viruses is sparse. We describe here Sulfolobus filamentous virus 1 (SFV1), a membrane-enveloped virus infecting Sulfolobus shibatae. The virus encodes two major coat proteins which display no apparent sequence similarity with each other or with any other proteins in databases. We have used cryo-electron microscopy at 3.7 Å resolution to show that these two proteins form a nearly symmetrical heterodimer, which wraps around A-form DNA, similar to what has been shown for SIRV2 and AFV1, two other archaeal filamentous viruses. The thin (∼ 20 Å) membrane of SFV1 is mainly archaeol, a lipid species that accounts for only 1% of the host lipids. Our results show how relatively conserved structural features can be maintained across evolution by both proteins and lipids that have diverged considerably.
不断以惊人的速度发现感染极端环境中古菌的不同形式的病毒，这表明目前对这些病毒的采样还很稀疏。我们在这里描述了感染 Sulfolobus shibatae 的膜包被病毒 Sulfolobus filamentous virus 1（SFV1）。该病毒编码两种主要的外壳蛋白，它们彼此之间没有明显的序列相似性，也与数据库中的任何其他蛋白质没有明显的序列相似性。我们已经使用 3.7Å 的分辨率冷冻电镜显示这两种蛋白形成了几乎对称的异二聚体，该异二聚体包裹在 A 型 DNA 周围，类似于已经显示的两种其他古菌丝状病毒 SIRV2 和 AFV1。SFV1 的薄（约 20Å）膜主要由 archaeol 组成，它是一种脂质，仅占宿主脂质的 1%。我们的结果表明，相对保守的结构特征如何通过已经明显分化的蛋白质和脂质在进化中得以维持。
