Structural insights into a spindle-shaped archaeal virus with a sevenfold symmetrical tail.
Structural insights into a spindle-shaped archaeal virus with a sevenfold symmetrical tail.
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对一种具有七重对称尾巴的纺锤形古菌病毒的结构洞察。
DOI：
10.1073/pnas.2119439119
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发表时间：
2022-08-02
影响因子：
11.1
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中科院分区：
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梭形病毒是最突出的古细菌病毒之一，广泛分布于不同的栖息地。在这里，我们提出了一个纺锤形的病毒（SSV 19），感染超嗜热古菌的结构。我们的研究结果表明，SSV 19是由七个左手螺旋链从一个不寻常的七重对称尾，与病毒吸附到宿主细胞。尾穗含有一个推定的甘露聚糖内切酶结构域，该结构域可能结合或降解细胞膜上含甘露糖的聚糖链。尾喷嘴蛋白类似于疱疹病毒和噬菌体门户的茎和剪辑结构域。这些发现揭示了纺锤形病毒的形态发生和宿主进入的重要线索，并暗示了古细菌、细菌和真核病毒之间的进化关系。具有纺锤形病毒体的肠病毒在极其多样化的环境中是丰富和广泛的。然而，获得纺锤形病毒的高分辨率结构的努力一直不成功。在这里，我们提出了结构的SSV 19，一个纺锤形的病毒感染的超嗜热古菌硫化叶菌属E11-6。我们的近原子结构揭示了一个不寻常的七重对称病毒尾巴组成的尾钉，喷嘴和衔接蛋白。纺锤形衣壳壳由七条左手螺旋链形成，由疏水性主要衣壳蛋白构成，从高度糖基化的尾部组装体发出。相邻链之间的滑动导致病毒粒子大小的变化。SSV 19感染细胞的超薄切片显示，SSV 19病毒粒子在穿透S层后通过尾部吸附到宿主细胞膜上。尾穗窝藏一个假定的甘露聚糖内切酶结构域，其与多形拟杆菌甘露聚糖内切酶具有结构相似性。在尾部和衣壳壳之间的疏水裂缝中观察到甘油二植烷基甘油四醚脂质分子。喷嘴蛋白类似于疱疹病毒和噬菌体门户的茎和剪辑结构域，这意味着古细菌，细菌和真核病毒之间的进化关系。
Spindle-shaped viruses are among the most prominent archaeal viruses and widespread in diverse habitats. Here, we present the structure of a spindle-shaped virus (SSV19) that infects a hyperthermophilic archaeon. Our results show that SSV19 is formed by seven left-handed helical strands starting from an unusual sevenfold symmetrical tail, with which the virus adsorbs to the host cell. The tailspike harbors a putative endo-mannanase domain, which presumably binds or degrades mannose-containing glycan chains on the cell membrane. The tail nozzle protein resembles the stem and clip domains of the portals of herpesviruses and bacteriophages. These findings shed significant light on the morphogenesis of and host entry by spindle-shaped viruses and imply an evolutionary relationship among the archaeal, bacterial, and eukaryotic viruses. Archaeal viruses with a spindle-shaped virion are abundant and widespread in extremely diverse environments. However, efforts to obtain the high-resolution structure of a spindle-shaped virus have been unsuccessful. Here, we present the structure of SSV19, a spindle-shaped virus infecting the hyperthermophilic archaeon Sulfolobus sp. E11-6. Our near-atomic structure reveals an unusual sevenfold symmetrical virus tail consisting of the tailspike, nozzle, and adaptor proteins. The spindle-shaped capsid shell is formed by seven left-handed helical strands, constructed of the hydrophobic major capsid protein, emanating from the highly glycosylated tail assembly. Sliding between adjacent strands is responsible for the variation of a virion in size. Ultrathin sections of the SSV19-infected cells show that SSV19 virions adsorb to the host cell membrane through the tail after penetrating the S-layer. The tailspike harbors a putative endo-mannanase domain, which shares structural similarity to a Bacteroides thetaiotaomicro endo-mannanase. Molecules of glycerol dibiphytanyl glycerol tetraether lipid were observed in hydrophobic clefts between the tail and the capsid shell. The nozzle protein resembles the stem and clip domains of the portals of herpesviruses and bacteriophages, implying an evolutionary relationship among the archaeal, bacterial, and eukaryotic viruses.