N-终端域形态和域相互作用对RfaH折叠切换的影响
1Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St Johns, NL, Canada.
Proteins
|October 14, 2024
概括
RfaH蛋白使用域解离和折叠切换进行转录和翻译. 在N终端域中的一个改造的β-hairpin降低了域分离所需的温度,帮助RfaH功能.
科学领域:
- 结构生物学是结构生物学.
- 分子生物物理学的分子生物物理学.
- 蛋白质动力学 蛋白质动力学
背景情况:
- RfaH是一种转化蛋白质,对转录调节和翻译启动至关重要.
- 它的功能经历了合域解离和折叠切换.
- N-终端域 (NTD) 和C-终端域 (CTD) 在与RNA聚合酶 (RNAP) 结合时改变形状.
研究的目的:
- 研究NTD的β-hairpin (β3-β4) 在触发RfaH域解离中的作用.
- 模拟RfaH和一个修改变体 (H1) 的热展开和域分离.
- 分析从开放状态到关闭状态的反向折叠开关.
主要方法:
- 同一性建模以创建H1变体与改造的β3-β4发针.
- 所有基于原子物理的模拟与基于结构的潜力.
- 由CTD热展开驱动的域分离的模拟.
- 对温度依赖的折叠切换动力学的分析.
主要成果:
- 与自由RfaH相比,H1变体在较低的温度下显示出CTD稳定性降低和域解离.
- 没有观察到完全重新折叠到全β状态,这表明针头的改变有助于但不仅仅是驱动解离.
- 折叠切换动力学是温度依赖的,在快速切换的最佳温度下,两个折叠的稳定性都降低了.
结论:
- 在NTD的β3-β4发针的形状变化对于启动RfaH域解离很重要.
- 域间相互作用和NTD形状变化共同调节RfaH的功能结构转变.
- 对于高效的RfaH折叠切换,平衡动力陷和不稳定性,存在最佳温度.
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