沙佩罗宁复合体与一个新折叠的蛋白质封装在折叠室内
D K Clare1, P J Bakkes, H van Heerikhuizen
1Department of Crystallography and Institute for Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
Nature
|January 6, 2009
概括
像GroEL-GroES这样的Chaperonins通过封装基板来帮助蛋白质折叠. 新的结构揭示了菌体T4蛋白gp23是如何封闭的,显示了沙佩罗宁在容纳大型蛋白质方面的灵活性.
科学领域:
- 结构生物学 结构生物学
- 分子陪伴者分子陪伴者
- 蛋白质折叠 蛋白质的折叠
背景情况:
- 沙佩罗宁,如大肠杆菌中的GroEL-GroES,是促进蛋白质折叠的必要细胞机器.
- 这些复合体结合并封装展开或错误折叠的蛋白质,为重新折叠提供受控的环境.
- 菌体T4利用一种特定的沙佩罗宁系统,包括gp31,折叠其主要囊蛋白,gp23.
研究的目的:
- 为了可视化一个沙佩罗宁折叠室内的基质蛋白的构造.
- 阐明像gp23.3这样的大型病毒蛋白质的沙佩罗宁介导折叠的结构基础.
主要方法:
- 确定gp23-chaperonin复合物的高分辨率结构.
- 捕获的蛋白质的快照,无论是最初的捕获状态还是最后的折叠状态,都在沙佩罗宁室内.
主要成果:
- 想象gp23的结构被封装在沙佩罗宁折叠室内.
- 观察到,沙佩罗宁腔扩大以容纳大而长长的gp23单体.
- 证明GroEL-GroES综合体,尽管扩张,只是足以容纳gp23.3.
结论:
- 沙佩罗宁结构是动态的,可以扭曲以包围大型生理基质蛋白质.
- 沙佩罗宁室的有限尺寸解释了为gp23折叠而对菌体T4的gp31联合沙佩罗宁的特殊要求.
- 对沙佩罗宁基质复合体的结构洞察力有助于更好地理解蛋白质折叠机制.
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