索达林结合的eEF2释放了CRPV IRES上的自发前向和逆向转位
1Department of Biological Sciences, Auburn University, Auburn, AL36849, USA.
Nucleic acids research
|June 7, 2023
概括
基因间区域内部核糖体进入点 (IGR IRES) 促进蛋白质合成. 延长因子2 (eEF2) 驱动IRES转位,而抗真菌sordarin可实现高效,热驱动的核糖体运动.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 跨基因区域的Discistroviridae的内部核糖体进入部位 (IGR IRES) 独立于规范启动因子启动蛋白质合成.
- 由延长因子2 (eEF2) 介导的IRES转移代表了一个独特的因子催化转化步骤.
- 在IRES介导的翻译过程中了解核糖体构造动态对于破译非正规蛋白质合成至关重要.
研究的目的:
- 在单分子水平上研究麻病毒IRES (CrPV IRES) 转化过程中真核核糖核体的构造动态.
- 阐明延长因子2 (eEF2) 在促进IRES介导翻译期间前向和反向转位中的作用.
- 确定抗真菌sordarin对eEF2-核糖体相互作用和IRES转位效率的影响.
主要方法:
- 通过标记核糖体RNA (rRNA) 来开发单分子观测系统.
- 使用开发的系统监测核糖体构造和翻译动态.
- 研究eEF2对核糖体转位的度依赖作用.
- 分析索达林对eEF2-核糖体复合体和IRES转位的影响.
主要成果:
- 在转移前的80S-IRES核糖体主要采用半旋转的形状,在旋转和非旋转状态之间自发交换.
- eEF2以以EF2度依赖的方式促进了前向和反向核糖体转位.
- 索达林稳定了eEF2在核糖体上的扩展形状,使每个结合事件中的多个转位循环成为可能.
- 在sordarin的存在下,IRES转位在没有GTP水解或酸盐释放的情况下进行,这表明热驱动的运动.
结论:
- 在CrPV IRES介导的翻译过程中,eEF2积极促进前向和反向转位.
- 索达林通过稳定eEF2并促进核糖体形状变化,显著增强IRES转位.
- 在CRPV IRES转移的中期和后期阶段,特别是在sordarin的存在下,很可能是热驱动的过程,eEF2可以解锁.
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