参与Fe-S集群生物发生的专门Hsp70/Hsp40复合体内的核酸依赖相互作用
Jin Hae Kim1, T Reid Alderson, Ronnie O Frederick
1Mitochondrial Protein Partnership, Center for Eukaryotic Structural Genomics, and ‡Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States.
Journal of the American Chemical Society
|August 2, 2014
概括
HscB 的 HPD 基因与 ATP 结合的 HscA 直接相互作用,而 HscB 中的第二个结合位点与 ATP 结合的 HscA 直接相互作用.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- Hsp70类型的陪伴者和Hsp40类型的共同陪伴者对于蛋白质平衡至关重要.
- 这些陪伴者之间的精确相互作用机制仍然不完全理解.
- 大肠杆菌 HscA 和 HscB 是专门的陪伴者,参与铁硫集群转移.
研究的目的:
- 阐明HscA和HscB之间的ATP/ADP依赖相互作用机制.
- 确定涉及HscA-HscB复合体形成的特定域和残留物.
- 了解HPD图案在HSCB功能中的作用.
主要方法:
- 使用溶液NMR光谱学研究HscA-HscB相互作用.
- 用于改变 HscB.HscB 的 HPD 动机,使用了位点定向的突变发生.
- 进行ATP水解试验以评估突变的功能影响.
主要成果:
- 包括HPD动机在内的HscB的J域的NMR信号在添加ATP结合的HscA时被扩大,但不是与ADP结合的HscA.
- 一种HscB变体具有改变的HPD动机 (HscB(H32A,P33A,D34A)) 显示没有显著的NMR信号变化,并取消了HscA的ATP水解刺激.
- 在HscB的C末端区域中的153-171残留物也在与HscA相互作用时显示出NMR扰动,表明第二个结合点.
结论:
- HscB 的 HPD 基因与 ATP 结合的 HscA 直接相互作用.
- 对于HscA来说,一个次要的,不太依赖于核酸的结合部位位于HscB的C端区域.
- 这些发现为Hsp70-Hsp40监护人合作的结构基础提供了关键的见解.
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