Structural organization of a filamentous influenza A virus
Structural organization of a filamentous influenza A virus
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DOI：
10.1073/pnas.1002123107
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发表时间：
2010-06-08
影响因子：
11.1
通讯作者：
Rosenthal, Peter B.
中科院分区：
文献类型：
--
作者：
Calder, Lesley J.;Wasilewski, Sebastian;Rosenthal, Peter B.
流感是一种有脂质包膜的多形性病毒。我们结合联合收割机和冷冻水化病毒粒子的图像分析来确定丝状甲型流感病毒的结构组织。流感A/Udorn/72病毒粒子是直径高度均匀的囊状或丝状颗粒。我们发现，邻近膜的基质层是M1蛋白的有序螺旋，其与周围包膜的密切相互作用决定了病毒粒子的形态。包装基因组片段的核糖核蛋白颗粒（RNP）在病毒内部的一端形成锥形组装。神经氨酸酶的数量比血凝素少，聚集成斑块，通常存在于病毒体末端，与RNP附着相对。在低pH值下孵育病毒会导致丝状形态的损失，在此期间，我们观察到基质层从其螺旋状、膜相关形式到病毒颗粒内部的多层螺旋结构的结构转变。病毒的极性组织为病毒体在宿主膜上出芽期间的组装提供了模型。A/Aichi/68 X-31病毒粒子的图像和断层图显示了这些结论对非丝状病毒粒子的普遍性。
Influenza is a lipid-enveloped, pleomorphic virus. We combine electron cryotomography and analysis of images of frozen-hydrated virions to determine the structural organization of filamentous influenza A virus. Influenza A/Udorn/72 virions are capsule-shaped or filamentous particles of highly uniform diameter. We show that the matrix layer adjacent to the membrane is an ordered helix of the M1 protein and its close interaction with the surrounding envelope determines virion morphology. The ribonucleoprotein particles (RNPs) that package the genome segments form a tapered assembly at one end of the virus interior. The neuraminidase, which is present in smaller numbers than the hemagglutinin, clusters in patches and are typically present at the end of the virion opposite to RNP attachment. Incubation of virus at low pH causes a loss of filamentous morphology, during which we observe a structural transition of the matrix layer from its helical, membrane-associated form to a multilayered coil structure inside the virus particle. The polar organization of the virus provides a model for assembly of the virion during budding at the host membrane. Images and tomograms of A/Aichi/68 X-31 virions show the generality of these conclusions to non-filamentous virions.