细菌群体感应转录因子的结构复杂化与费罗蒙和DNA
Rong-guang Zhang1, Katherine M Pappas, Terina Pappas
1Bioscience Division/Structural Biology Center, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
Nature
|June 28, 2002
概括
研究人员确定了TraR蛋白质的结构,这是Agrobacterium tumefaciens的一个关键调节器,与其激素N-acylhomoserine乳结合. 这揭示了细菌通信系统如何控制基因表达和细胞行为.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 蛋白质细菌利用N-acylhomoserine乳 (AHLs) 作为信号分子来感知人口密度.
- AHLs调节各种细胞过程,包括生物发光,生物膜形成和致病.
- 卢克斯R型的转录调节器对于调解AHL依赖反应至关重要.
研究的目的:
- 阐明由LuxR型蛋白质识别AHL识别和DNA结合的结构基础.
- 提供对蛋白质细菌中定数感应的分子机制的见解.
主要方法:
- 采用X射线晶体学来确定TraR蛋白的结构.
- 该结构的分辨率为1.66安格斯特罗姆.
- 该综合体包括TraR蛋白,其相似的费洛蒙N-3-oxooctanoyl-L-homoserine乳 (OOHL),以及TraRDNA结合部位.
主要成果:
- 结构显示,TraR具有不同的N-终端 (联结) 和C-终端 (DNA结合) 域.
- N-终端域采用一个α/β/α三明治折叠,容纳OOHL激素.
- C终端域具有用于DNA相互作用的螺旋转螺旋图案,TraR二元体呈现出整体不对称的构造.
结论:
- 该结构提供了通过LuxR型调节器对激素结合和DNA相互作用的详细分子理解.
- 这项工作揭示了细菌中定数感应信号转导的结构复杂性.
- 这些发现有助于理解细菌的交流及其在各种生物过程中的作用.
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