通过时间解析的小角度X射线散射观察到的细菌 ribozyme 的多阶段崩
Joon Ho Roh1, Liang Guo, J Duncan Kilburn
1Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA. rohmio1973@gmail.com
Journal of the American Chemical Society
|July 6, 2010
概括
离子 (Mg2+) 对于 ribozyme 折叠至关重要,影响RNA 三级结构的形成. 特定的Mg2+度决定了折叠路径和速度,强调了电荷中和在早期结构转变中的作用.
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:
- ribozymes 需要紧,本地结构的细胞功能.
- RNA三级结构的形成始于阴子介导的电荷中和和分子崩.
- 了解驱动特定RNA崩的力量至关重要,但仍然不太了解.
研究的目的:
- 为了研究离子 (Mg2+) 在 ribozyme 折叠的早期阶段的作用.
- 阐明Mg2+度,电荷中和和RNA崩机制之间的关系.
- 描述Mg2+依赖性崩对 ribozyme 折叠动力学和中间结构的影响.
主要方法:
- 时间解析的小角度X射线散射 (SAXS) 用于监测 ribozyme 折叠动态.
- 在不同的Mg2+度下 (1mM到5mM) 研究了Azoarcus I组的 ribozyme.
- 使用尿素的部分变性被用来探测非原生相互作用的影响.
主要成果:
- 在5毫米的Mg2+下,Azoarcus ribozyme迅速形成紧的结构 (<1 ms).
- 较低的Mg2+度 (1mM) 导致结构延伸,折叠速度较慢.
- 2+度调节了展开状态的组合,影响了折叠动力学,并引入了崩行为的交叉.
- 中间组合的灵活性增加与更快折叠的种群相关.
结论:
- 首选的RNA崩机制取决于Mg2+依赖电荷中和的程度.
- 展开集团内的非本地相互作用有助于异质的 ribozyme 折叠路径.
- 早期阶段的三级结构形成对阴离子度和展开状态的性质敏感.
相关概念视频
Ribozymes
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can be...
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Ribozymes can be...
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