在3.2A分辨率下,一个 prokaryotic 虚拟质子的结构
Yiling Fang1, Hariharan Jayaram, Tania Shane
1Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA.
Nature
|July 7, 2009
概括
大肠杆菌使用氨酸依赖的系统来生存胃酸. 研究人员确定了AdiC蛋白质的晶体结构,揭示了其向外开放的形状和与其他传送器的相似之处.
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:
- 像大肠杆菌这样的肠道细菌必须在胃的酸性环境中生存,才能在哺乳动物的肠道中定居.
- 细菌中的抗酸性往往涉及到专门的系统,例如大肠杆菌中的阿金依赖系统.
- 这种系统利用阿金脱碳化来维持细胞内pH稳态.
研究的目的:
- 阐明参与细菌酸性耐药性的氨酸依赖转运体 (AdiC) 的结构基础.
- 了解阿迪C的运输机制,这是阿金依赖系统的关键组成部分.
- 提供高分辨率的结构见解APC超级家族的膜传送器.
主要方法:
- 采用X射线晶体学来确定AdiC蛋白质的结构.
- 晶体结构的分辨率为3.2 Å.
- 结构显示了蛋白质在一个向外开放的,无基质的外形.
主要成果:
- 内部膜载体AdiC的晶体结构以3.2 Å的分辨率确定.
- 观察到AdiC处于向外开放的,无基质的状态.
- AdiC的跨膜架构与与之无关的运输蛋白家族有着显著的相似性.
结论:
- 确定的结构为AdiC和更广泛的APC超级家族的机制提供了关键的见解.
- 结构上的相似性表明,在不同的运输器家族中,潜在的运输原则可以得到保护.
- 了解AdiC的结构有助于理解细菌在酸性环境中的生存策略.
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