Delicate structural coordination of the Severe Acute Respiratory Syndrome coronavirus Nsp13 upon ATP hydrolysis
Delicate structural coordination of the Severe Acute Respiratory Syndrome coronavirus Nsp13 upon ATP hydrolysis
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DOI：
10.1093/nar/gkz409
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发表时间：
2019-07-09
影响因子：
14.9
通讯作者：
Rao, Zihe
中科院分区：
文献类型：
--
作者：
Jia, Zhihui;Yan, Liming;Rao, Zihe
迄今为止，赋予针对冠状病毒（CoV）的强减毒的有效治疗性治疗仍然难以捉摸。在所有潜在的药物靶点中，CoV的解旋酶被认为是最重要的靶点之一。在这里，我们首先提出了全长Nsp 13解旋酶的SARS冠状病毒（SARS-Nsp 13）的结构，并调查其五个结构域的结构协调，以及这些如何有助于其易位和解旋活动。根据H/D交换实验表征的Upf 1类解旋酶成员在溶液中的3种不同结构状态，即底物状态（与AMPPNP结合的SARS-Nsp 13-dsDNA）、过渡状态（与ADP-AlF 4-结合）和产物状态（与ADP结合），提出了Upf 1类解旋酶成员的转位模型.我们观察到1A结构域上的β 19-β 20环直接参与解旋过程。此外，我们已经证明，RNA依赖的RNA聚合酶（RdRp），SARS-Nsp 12，可以提高解旋酶活性的SARS-Nsp 13通过直接与它的相互作用。相互作用的区域被鉴定出来，并且可以被认为是跨冠状病毒的共同区域，这为冠状病毒的复制和转录复合体（RTC）提供了新的见解。
To date, an effective therapeutic treatment that confers strong attenuation toward coronaviruses (CoVs) remains elusive. Of all the potential drug targets, the helicase of CoVs is considered to be one of the most important. Here, we first present the structure of the full-length Nsp13 helicase of SARS-CoV (SARS-Nsp13) and investigate the structural coordination of its five domains and how these contribute to its translocation and unwinding activity. A translocation model is proposed for the Upf1-like helicase members according to three different structural conditions in solution characterized through H/D exchange assay, including substrate state (SARS-Nsp13-dsDNA bound with AMPPNP), transition state (bound with ADP-AlF4-) and product state (bound with ADP). We observed that the beta 19-beta 20 loop on the 1A domain is involved in unwinding process directly. Furthermore, we have shown that the RNA dependent RNA polymerase (RdRp), SARS-Nsp12,can enhance the helicase activity of SARS-Nsp13 through interacting with it directly. The interacting regions were identified and can be considered common across CoVs, which provides new insights into the Replication and Transcription Complex (RTC) of CoVs.