Structural and Electrostatic Characterization of Pariacoto Virus: Implications for Viral Assembly
Structural and Electrostatic Characterization of Pariacoto Virus: Implications for Viral Assembly
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DOI：
10.1002/bip.21168
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发表时间：
2009-07-01
期刊：
影响因子：
2.9
通讯作者：
Harvey, Stephen C.
中科院分区：
文献类型：
--
作者：
Devkota, Batsal;Petrov, Anton S.;Harvey, Stephen C.
我们提出了第一个全原子模型的T = 3病毒，pariacoto病毒（PaV），这是一个无包膜，二十面体RNA病毒和Nodaviridae家族的成员的结构。该模型是晶体结构的扩展，它揭示了约88%的蛋白质结构，但仅揭示了约35%的RNA结构。新的建模方法，结合粗粒度和全原子的方法，需要开发模型。对替代模型的评估证实了我们先前的观察，即衣壳蛋白的聚阳离子N-和C-末端尾部必须深入穿透到病毒的核心，在那里它们通过中和相当大一部分RNA电荷来稳定结构。这使我们提出了一个小的二十面体RNA病毒的组装模型：蛋白质尾部与RNA的非特异性结合导致复合物的崩溃，以一种让人想起DNA缩合的方式。球状蛋白结构域被排除在凝聚相之外，但被束缚在凝聚相上，因此它们聚集在凝聚相周围的壳中，在那里它们的浓度足够高以触发寡聚化和成熟病毒的形成。(C)2009 Wiley Periodicals，Inc. Biopolymers 91：530-538，2009.
We present the first all-atom model for the structure of a T = 3 virus, pariacoto virus (PaV), which is a nonenveloped, icosahedral RNA virus and a member of the Nodaviridae family. The model is an extension of the crystal structure, which reveals about 88% of the protein structure but only about 35% of the RNA structure. New modeling methods, combining coarse-grained and all-atom approaches, were required for developing the model. Evaluation of alternative models confirms our earlier observation that the polycationic N- and C-terminal tails of the capsid proteins must penetrate deeply into the core of the virus, where they stabilize the structure by neutralizing a substantial fraction of the RNA charge. This leads us to propose a model for the assembly of small icosahedral RNA viruses: nonspecific binding of the protein tails to the RNA leads to a collapse of the complex, in a fashion reminiscent of DNA condensation. The globular protein domains are excluded from the condensed phase but are tethered to it, so they accumulate in a shell around the condensed phase, where their concentration is high enough to trigger oligomerization and formation of the mature virus. (C) 2009 Wiley Periodicals, Inc. Biopolymers 91: 530-538, 2009.