活动部位的改造伴随着SUMO E1 E1中酸键的形成
Shaun K Olsen1, Allan D Capili, Xuequan Lu
1Structural Biology, Sloan-Kettering Institute, New York, New York 10065, USA.
Nature
|February 19, 2010
概括
这项研究揭示了SUMO蛋白的E1酶激活背后的结构机制. 晶体结构显示了E1酶如何重塑其催化域以形成关键的硫键.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 通过两步过程,E1酶对于激活泛素 (Ub) 和泛素类蛋白质 (Ubl) 是必不可少的.
- 这一过程涉及碳氧终端腺化和与催化氨酸残留物形成硫键.
- 在E1酶功能中的这些关键中间体的结构基础在很大程度上是未知的.
研究的目的:
- 为了阐明E1酶介导的SUMO (小Ubiquitin类修饰剂) 蛋白质激活的基础结构机制.
- 提供高分辨率的结构洞察力,了解基化和铁键形成的中间体.
主要方法:
- 使用X射线晶体学来确定人类SUMO E1.1.的结构.
- 分析了含有SUMO腺酸盐和四面体中间类型的复合物,分辨率为2.45和2.6 Å.
- 进行了突变分析和生化分析,以验证观察到的结构变化的功能意义.
主要成果:
- 晶体结构揭示了在铁键形成过程中E1催化氨酸域的动态重新定位.
- 在腺化后,Cys域发生了显著的130度旋转,由侧链接触到ATP.Mg的释放驱动.
- 关键的结构元素,包括参与催化过程的螺旋和循环,经历了大量的改造,促进了从腺化转变为铁键形成的过程.
结论:
- 这项研究提供了SUMO激活过程中E1酶动态构造变化的第一个结构证据.
- 这些发现解释了E1酶如何通过域旋转和结构重塑从化转变为铁键形成.
- 鉴定的机制可能在不同的E1酶中保持一致,为Ub/Ubl激活提供了一个一般模型.
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