Structural morphing in a symmetry-mismatched viral vertex
Structural morphing in a symmetry-mismatched viral vertex
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DOI：
10.1038/s41467-020-15575-4
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发表时间：
2020-04-06
影响因子：
16.6
通讯作者：
Rao, Venigalla B.
中科院分区：
文献类型：
--
作者：
Fang, Qianglin;Tang, Wei-Chun;Rao, Venigalla B.
大型生物结构是由较小的、通常是对称的子结构组装而成的。然而，子结构之间的不对称性对于生物功能至关重要。一种极端形式的不对称性，即插入 5 重对称衣壳顶点的 12 重对称十二聚门户复合体，在许多二十面体病毒中被发现，包括尾噬菌体、疱疹病毒和古细菌病毒。该顶点对于驱动衣壳组装、DNA 包装、尾部附着和基因组喷射至关重要。在这里，我们报告了噬菌体 T4 对称不匹配门顶点的近原子原位结构。值得注意的是，门户的局部结构变形以补偿对称失配，在不同的衣壳环境中形成类似的相互作用，同时在结构的其余部分保持严格的对称性。这创造了一个独特且异常动态的对称不匹配顶点，这是构建传染性病毒颗粒的核心。
Large biological structures are assembled from smaller, often symmetric, sub-structures. However, asymmetry among sub-structures is fundamentally important for biological function. An extreme form of asymmetry, a 12-fold-symmetric dodecameric portal complex inserted into a 5-fold-symmetric capsid vertex, is found in numerous icosahedral viruses, including tailed bacteriophages, herpesviruses, and archaeal viruses. This vertex is critical for driving capsid assembly, DNA packaging, tail attachment, and genome ejection. Here, we report the near-atomic in situ structure of the symmetry-mismatched portal vertex from bacteriophage T4. Remarkably, the local structure of portal morphs to compensate for symmetry-mismatch, forming similar interactions in different capsid environments while maintaining strict symmetry in the rest of the structure. This creates a unique and unusually dynamic symmetry-mismatched vertex that is central to building an infectious virion.