在伴蛋白GroEL和GroES中的核酸结合区域的识别
J Martin1, S Geromanos, P Tempst
1Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York 10021.
Nature
|November 18, 1993
概括
护卫者GroEL-GroES系统促进了大肠杆菌中的蛋白质折叠. 这项研究表明,GroES也结合ATP,这可能对GroEL至关重要.
科学领域:
- 分子生物学分子生物学
- 蛋白质折叠机制 蛋白质折叠机制
- 生物化学 生物化学
背景情况:
- 护卫蛋白GroEL及其辅因子GroES对于大肠杆菌中的蛋白质折叠至关重要.
- 它们形成一个复合体,将未折叠的蛋白质结合在一起,促进它们在ATP水解时释放以折叠.
研究的目的:
- 在GroEL和GroES子单元中识别核酸结合域.
- 研究核酸结合在GroEL-GroES蛋白质折叠机器中的作用.
主要方法:
- 位点定向的突变发生和用阿齐多-ATP标记蛋白质.
- 蛋白酶稳定性测试用于识别核酸结合域.
- 在GroES中分析ATP结合亲和力和合作性.
主要成果:
- 在GroEL中确定了一种蛋白酶稳定的核酸结合域 (残留物153-531),与Tyr 477进行亚酸-ATP交叉链接.
- 发现GroES可以与GroEL相似的亲和力合作结合ATP.
- 在Tyr 71中,GroES的亚核酸标记发生在一个稳定的6.5K域中,当GroES与GroEL结合时,在残留物32的裂变被阻止.
结论:
- GroEL子单位包含一个特定的核酸结合域,对其功能至关重要.
- GroES还结合ATP,这表明它不仅仅是一个lid,还具有更复杂的作用.
- 对GroES的ATP结合可能会为高效的ATP结合和水解,优化基质蛋白释放和折叠的GroEL环进行炼.
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