快速键的形成和释放由核糖体大亚单元
Letian Bao1, Anthony C Forster1
1Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
The Journal of biological chemistry
|June 5, 2025
概括
研究人员使用甲醇和PEG在50S核糖体子单元上加速缓慢的键形成和释放反应. 这些发现支持早期的核糖体进化理论,并有助于未来的机理学研究.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 键形成和基释放发生在50S子单元的基转移酶中心.
- 这些反应的现有模型是基于50S和70S核糖体结构.
- 由50S亚单元催化的反应比70S核糖体的反应要慢得多.
研究的目的:
- 研究加快键形成和由50S核糖体子单元催化的释反应的方法.
- 为了比较不同化学条件对这些核糖体功能的影响.
- 提供关于核糖体及其催化机制演化的见解.
主要方法:
- 利用胺素作为一种模型基质,用于在甲醇和聚乙烯糖醇 (PEG) 存在时由50S子单元催化形成键.
- 在乙中的50S子单元上使用tRNAPhe或CCA三核酸作为模型基质进行研究的基释放反应.
- 在各种溶剂条件下 (甲醇,PEG,乙) 比较反应速率,以评估它们对基质结合和催化的影响.
主要成果:
- 在33%的甲醇和20%PEG的水溶液中,在50S子单元上与胺素形成近生理速率.
- 甲醇显著加快了基质与50S P位点的结合,而PEG也提高了反应速度.
- 在30%的乙中观察到快速释模型反应,但不与PEG,表明键形成和释放的独特机制.
- 在水性条件下,报告了50S和70S子单元之间的可比基转移率.
结论:
- 甲醇和PEG可以显著提高由50S核糖体子单元催化的键形成的速度.
- 在50S子单元上,不同的机制控制了键的形成和的释放.
- 这些发现支持了关于早期核糖体进化的假设,并为进一步的机理学研究提供了基础.
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