ATP与蛋白质体ATPases结合在一起,具有明显的功能效应,这意味着有序的反应周期
David M Smith1, Hugo Fraga, Christian Reis
1Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. dsmith2@hsc.wvu.edu
Cell
|February 22, 2011
概括
蛋白质酶体是蛋白质酶体的组成部分.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 26S蛋白酶体是蛋白质降解的关键细胞机器.
- 它的功能由AAA ATPase子单元调节,包括古生物中的蛋白酶激活核酶 (PAN).
研究的目的:
- 研究ATP结合和水解在蛋白酶激活核酶 (PAN) 功能中的作用.
- 阐明PAN与20S蛋白质组相互作用的机制.
主要方法:
- 使用生物化学分析研究了与PAN的核酸结合.
- 研究了不同核酸结合状态对PAN与20S蛋白酶和蛋白质基质结合的相互作用的影响.
- 检查了真核细胞26S蛋白质组的核酸依赖性.
主要成果:
- PAN将ATP结合成两对,呈现出三种不同的构造状态.
- 在基质结合和20S门开放中,当两个或四个ATP分子结合时,就会发生最佳的PAN活性.
- 四个ATP分子的结合减少了PAN的功能,这表明一种循环机制.
结论:
- 这些发现表明,蛋白酶调节的有序循环机制涉及两个ATPase子单元同时结合ATP.
- 这种机制解释了hexameric ATPases在heptameric 20S蛋白质组上的相互作用和"摇摆"运动.
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