对MarR类型调节器AbfR的反氧传感机制的结构洞察
Guijie Liu1,2, Xing Liu1,3, Hongjiao Xu1,2
1Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China.
Journal of the American Chemical Society
|January 15, 2017
概括
通过 Staphylococcus epidermidis AbfR 的氧化应激调节涉及氨酸的修饰. 可逆二硫化键,而不是过氧化, 抑制DNA结合, 揭示新的氧化还原传感机制.
科学领域:
- 微生物学
- 结构生物学
- 生物化学
背景情况:
- AbfR是Staphylococcus epidermidis中MARR家族转录调节者的一个主体.
- 它在氧化应激反应和毒性调节中起着至关重要的作用.
研究的目的:
- 在各种氧化状态下阐明AbfR的DNA结合机制.
- 了解 AbfR 的氧化还原调节的结构基础.
主要方法:
- 减少的AbfR/DNA复合物的X射线晶体学,过氧化的AbfR/DNA,和2-二硫化物交联的AbfR二聚体.
- 生物化学分析
主要成果:
- 与不可逆转的过氧化不同的是,可逆转的二硫化物修饰显著降低了AbfR的DNA结合能力.
- 一二硫化物和二二硫化物交叉连接的AbfR二聚体都具有生物学意义.
- 过氧化的AbfR保留了DNA结合,但在生物学上没有意义.
- 1-二硫化交叉连接削弱了DNA结合;2-二硫化交叉连接导致与DNA结合不相容的开放形状.
结论:
- AbfR的氧化还原调节涉及新的特征,包括二硫化键与过氧化对DNA结合的差异影响.
- 半氨酸的简洁氧化化学结构使得在AbfR中能够有效地感知和反应氧化应激.
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