一个Bag/Hsc70复合体的结构:Hsp70核酸交换因子的融合功能演变
H Sondermann1, C Scheufler, C Schneider
1Department of Cellular Biochemistry, Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany.
概括
在Hsp70共因子中的囊域与Hsp70 ATPase域结合,促进基质释放. 结构研究显示,在物种之间进行核酸交换的结构性切换机制是保存的.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 袋子域是真核体70千多达尔顿热冲击蛋白 (Hsp70) 护卫者的共因子.
- Hsp70s在蛋白质折叠和细胞蛋白质稳定中发挥着至关重要的作用.
- 通过核酸结合和水解来调节Hsp70的功能.
研究的目的:
- 阐明Bag域介导的Hsp70调节的结构基础.
- 为了了解Hsp70核酸交换的机制.
- 为了研究Hsp70辅因子相互作用的功能融合.
主要方法:
- 对Hsc70 ATPase域的X射线晶体 (1.9安格斯特罗姆分辨率) 与一个Bag域复杂化.
- 生物化学测试以评估Hsp70基质释放的情况.
- 用细菌Hsp70同源DnaK及其辅因子GrpE进行比较结构分析.
主要成果:
- 袋子域形成一个三螺旋捆绑,绑定Hsp70 ATPase域.
- 这种相互作用会诱导Hsp70中的结构转换,使其与核酸结合不相容.
- 这种机制在功能上是保留的,因为结构上不同的GrpE也会在DnaK中诱导类似的切换.
结论:
- 袋域作为核酸交换因子作用于Hsp70s,通过诱导保存的构造变化.
- 功能融合允许具有不同架构的蛋白调节Hsp70活动.
- 这项研究提供了对Hsp70伴侣调节和辅因子相互作用的结构性见解.
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