非原生基质蛋白质的多价值结合由 chaperonin GroEL 进行
G W Farr1, K Furtak, M B Rowland
1Howard Hughes Medical Institute and Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA.
Cell
|March 18, 2000
概括
护卫蛋白GroEL对于像Rubisco这样的严格蛋白质,至少需要三个结合点. 较不严格的蛋白质,如罗丹蛋白,与较少的部位结合,显示GroEL.
科学领域:
- 分子陪伴者分子陪伴者
- 蛋白质折叠 蛋白质的折叠
- 生物化学 生物化学
背景情况:
- 沙佩罗宁GroEL通过结合非原生基质来促进蛋白质折叠.
- GroEL的机制涉及ATP结合和可沙佩罗宁GroES相互作用.
- 参与基质结合的GroEL角域的数量尚不清楚.
研究的目的:
- 为了研究非原生蛋白与GroEL角域结合的固体几何学.
- 为了确定基底相互作用所需的最少的绑定高效域数量和排列.
主要方法:
- 利用了工程设计的GroEL环,其中结合了野生类型和结合缺陷突变的角域.
- 评估了用严格的 (马拉酸脱酶,鲁比斯科) 和不那么严格的 (罗丹) 基质蛋白质形成的二元复合体.
- 采用氧化交叉链接来物理确认Rubisco的多价值结合.
主要成果:
- 为了有效地结合严格的基板,至少需要三个连续的野生类型的顶点域.
- 不那么严格的基板罗丹尼斯只需要两个结合域,无论它们的排列如何.
- 通过交叉链接获得了多价值Rubisco与GroEL结合的直接证据.
结论:
- GroEL基质结合是多价值的,具有严格的蛋白质,需要多个相互作用点.
- 所需的结合域的数量与基质强度相关.
- 这项研究阐明了GroEL chaperonin系统对基质识别的定量方面.
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