一个Ran-binding域的结构与Ran结合到一个GTP模拟的Ran复杂:对核运输的影响
I R Vetter1, C Nowak, T Nishimoto
1Abteilung Strukturelle Biologie, Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany.
Nature
|March 17, 1999
概括
这是一种Ran蛋白质.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 结构生物学 结构生物学
背景情况:
- 蛋白质Ran是一种小的GTP结合蛋白,对核运输至关重要.
- 兰与兰结合蛋白和进口蛋白-β类分子相互作用,调节细胞过程.
- Ran-binding域 (RanBDs) 是参与这些相互作用的保存动机.
研究的目的:
- 阐明Ran与RanBP2相互作用的结构基础,RanBP2是核孔综合体的关键组成部分.
- 了解RanBDs调节Ran的GTPase活动及其在核运输中的作用的机制.
主要方法:
- 使用X射线晶体学来确定Ran与人类RanBP2的第一个Ran-binding域 (RanBD1) 复合的Ran与GTP类似物 (Ran x GppNHp) 结合的结构.
主要成果:
- 兰BD1共享了一个pleckstrin-homology域折叠.
- 在结构上,Ran x GppNHp的Switch-I区域类似于正规的Ras GppNHp.
- 兰的carboxy终端环绕RanBD1,形成一个"拥抱",将终端隔离,并促进Ran与运输因素的分离.
结论:
- 这种相互作用代表了Ras相关蛋白质的新型开关机制.
- 兰-RanBP2相互作用促进了 ranGAP 的 GTP 水解,调节了核运输.
- 这一发现为细胞运输中蛋白质与蛋白质相互作用的调节提供了新的见解.
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