Cryo-EM Structure of Influenza Virus RNA Polymerase Complex at 4.3 Å Resolution
Cryo-EM Structure of Influenza Virus RNA Polymerase Complex at 4.3 Å Resolution
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DOI：
10.1016/j.molcel.2014.12.031
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发表时间：
2015-03-05
期刊：
影响因子：
16
通讯作者：
Liu, Yingfang
中科院分区：
文献类型：
--
作者：
Chang, Shenghai;Sun, Dapeng;Liu, Yingfang
流感病毒基因组的复制和转录主要依赖于其RNA依赖的RNA聚合酶(RdRP)，该聚合酶由PA、PB1和PB2亚基组成。尽管被广泛研究，但RdRP复合体的潜在机制仍不清楚。在这里，我们报道了流感病毒RdRP亚复合体的生化特征，它由PA、PB1和PB2的N末端组成，它们在溶液中以二聚体的形式存在，并可以在vRNA启动子的调控下组装成四聚体。利用单粒子冷冻电子显微镜，我们在4.3埃处重建了RdRP四聚体复合体，突出了四聚体结构中单体之间的组装和界面。单个RdRP亚复合体包含所有特征基序，呈笼状结构。高通量突变图谱显示，寡聚体状态形成中涉及的残基对病毒生命周期至关重要。我们的结果为理解流感和其他负链RNA病毒的复制机制奠定了坚实的基础。
Replication and transcription of influenza virus genome mainly depend on its RNA-dependent RNA polymerase (RdRP), composed of the PA, PB1, and PB2 subunits. Although extensively studied, the underlying mechanism of the RdRP complex is still unclear. Here we report the biochemical characterization of influenza RdRP subcomplex comprising PA, PB1, and N terminus of PB2, which exist as dimer in solution and can assemble into a tetramer state, regulated by vRNA promoter. Using single-particle cryo-electron microscopy, we have reconstructed the RdRP tetramer complex at 4.3 angstrom, highlighting the assembly and interfaces between monomers within the tetrameric structure. The individual RdRP subcomplex contains all the characterized motifs and appears as a cage-like structure. High-throughput mutagenesis profiling revealed that residues involved in the oligomer state formation are critical for viral life cycle. Our results lay a solid base for understanding the mechanism of replication of influenza and other negative-stranded RNA viruses.