通道的开放孔状结构
Youxing Jiang1, Alice Lee, Jiayun Chen
1Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Nature
|May 31, 2002
概括
细胞离子通道通过一个关门机制打开和关闭,涉及孔螺旋体的结构变化. 这种曲运动调节离子流动,并在各种通道中保持.
科学领域:
- 结构生物学 结构生物学
- 分子生理学分子生理学
- 生物物理学的生物物理.
背景情况:
- 活细胞通过离子通道门精确地控制离子运输.
- 跨膜领域的形状变化对于通道孔隙开放至关重要.
研究的目的:
- 阐明通道门背后的结构机制.
- 为了研究KcsA (封闭) 和MthK (开放) 通道中的门转换.
主要方法:
- 关闭 (KcsA) 和开放 (MthK) 的通道结构的比较结构分析.
- 识别保护的氨基酸序列和涉及门的结构动机.
主要成果:
- 通道封锁涉及内部螺旋体中的"封锁链",它曲约30度.
- 在封闭状态下,内部螺旋环捆绑起来遮住孔隙;在开放状态下,它们向外伸展,形成一个宽的入口.
- 开放的形状通过将电场集中在选择性过器上来增强离子导电.
结论:
- 跨越多种通道,包括连接体和电压连接类型,存在一个通往门的共同结构基础.
- 观察到的封闭机制促进了高离子导电,并允许更大的分子进入孔隙.
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