通过SARS-CoV-2进行RNA封闭的机制
Gina J Park1, Adam Osinski1, Genaro Hernandez1
1Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Nature
|August 9, 2022
概括
SARS-CoV-2 使用一种非传统的RNA封闭机制,涉及病毒蛋白质nsp12,nsp9,nsp14和nsp16. 这一发现揭示了开发新的COVID-19抗病毒疗法的新目标.
科学领域:
- 病毒学
- 分子生物学
- 结构生物学
背景情况:
- SARS-CoV-2 RNA 基因组需要一个 5' 盖,以实现翻译,稳定性和免疫逃避.
- 之前尚不清楚病毒蛋白质对SARS-CoV-2RNA帽形成的确切机制.
研究的目的:
- 阐明SARS-CoV-2RNA帽合成的逐步过程.
- 识别参与RNA封闭的病毒非结构蛋白 (nsps).
- 探索封闭机制作为抗病毒目标的潜力.
主要方法:
- 在体外复制N7-和2'-O-甲基化的SARS-CoV-2RNA盖 (7MeGpppA2'-O-Me).
- 使用病毒编码的非结构蛋白 (nsps),包括nsp12,nsp9,nsp14和nsp16.
- 使用复制转录复合物的结构分析和反向遗传系统.
主要成果:
- nsp12的尼多病毒RdRp关联核基转移酶 (NiRAN) 域介导nsp9的RNAylation,形成一个共价RNA-蛋白中间体.
- NiRAN域将RNA转移到GDP,创建核心盖结构GpppA-RNA.
- 通过nsp14和nsp16的甲基化产生功能盖;nsp9的N端和NiRAN活性位点对于复制至关重要.
结论:
- SARS-CoV-2采用了一种不传统的RNA封闭机制,涉及一系列的nsps.
- 已确定的RNA封闭途径为抗COVID-19抗病毒药物开发提供了一个新的目标.
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