tRNASer3的双解码证明了核糖体解码中心的可塑性
Shruthi Krishnaswamy1,2, Shirin Akbar1, Daniel S D Larsson1
1Department of Cell and Molecular Biology, Uppsala University, BMC, P.O. Box 596, SE-75124, Uppsala, Sweden.
Nature communications
|June 26, 2025
概括
核糖体可以通过读取两个mRNA基而不是三个基来进行移. 一种特定的转移RNA (tRNA) 使用核糖体RNA (rRNA) 中的保存基来实现这种非正规解码.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 是一个遗传学.
背景情况:
- 核糖体框架转移是一个关键的翻译控制机制.
- 转移RNA (tRNA) 的非同源解码可以导致移.
- 由特定的tRNA-mRNA相互作用引起的移的机制尚不清楚.
研究的目的:
- 阐明由大肠杆菌tRNA^Ser3.3解码的非同胞的结构基础.
- 了解核糖体如何适应引发移的tRNA-mRNA相互作用.
- 为了研究保留的核糖体RNA基在解码忠实性中的作用.
主要方法:
- 单粒子冷电子显微镜 (cryo-EM) 的重建.
- 对大肠杆菌70S核糖体的结构分析.
- 对tRNA与同源 (AGC) 和非同源 (GCA) 编码子结合的研究.
主要成果:
- 冷-EM结构揭示了大肠杆菌tRNA^Ser3如何解码非同源的GCA编码子.
- 16S rRNA中的A1493模仿了第一个编码基,与tRNA反编码基形成Hoogsteen基对.
- 这种相互作用使前两个mRNA基与抗结合,使双重解码成为可能.
结论:
- 保存的基A1493在促进非同源解码和转移方面发挥着关键作用.
- 核糖体可以通过特定的rRNA-tRNA-mRNA相互作用来适应双重解码.
- 这种结构洞察力澄清了核糖体框架转移的机制.
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