一个独立于帽子的翻译增强 RNA 的晶体结构
Anna Lewicka1, Christina Roman1, Stacey Jones1
1Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA.
Nucleic acids research
|August 7, 2023
概括
植物病毒使用上限独立的翻译元素 (CITEs) 来启动翻译. 我们确定了Peenation马赛克病毒2 (PEMV2) RNA CITE的结构,揭示了真核细胞启动因子4E (eIF4E) 识别的新机制.
科学领域:
- 分子生物学分子生物学
- 病毒学 病毒学
- 结构生物学 结构生物学
背景情况:
- 细胞mRNA通常使用5'帽结构通过细胞启动因子4E (eIF4E) 启动翻译.
- 许多植物病毒通过使用cap-independent翻译元素 (CITEs) 绕过这一点,通常位于3'未翻译区域.
- 假设CITE的Panicum马赛克病毒翻译元素 (PTE) 类,具有G丰富的膨胀和C丰富的结,可以形成eIF4E相互作用的伪结.
研究的目的:
- 为了阐明由Peenation马赛克病毒2 (PEMV2) RNA PTE介导的顶部独立翻译的结构基础.
- 了解这种CITE如何与真核细胞启动因子4E (eIF4E) 相互作用.
主要方法:
- 获得了 PEMV2 RNA PTE 的晶体结构,并与一个结构性伴侣 (Fab BL3-6) 结合起来.
- 利用SHAPE分析探测RNA结构并识别反应残留物.
- 分析结构数据以确定PTE内部的交互网络.
主要成果:
- 晶体结构揭示了G丰富和C丰富区域之间的复杂相互作用网络,与伪节点不同.
- 确定了一个短的平行双重体,促进了关键的瓜诺辛残留物的挤出.
- 这种挤出的瓜诺辛被认为对eIF4E识别至关重要.
结论:
- 对于eIF4E结合,PEMV2 PTE使用了一个独特的结构图案,而不是伪结.
- 这种结构提供了一个暴露瓜诺辛残留物用于翻译因子识别的机制.
- 在同类PTE元素中保留的特征表明这种架构是进化维护的.
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