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来自Bacillus subtilis的旗定位蛋白MotsS中的依赖的形状变化
Norihiro Takekawa1, Ayaka Yamaguchi1, Koki Nishiuchi1
1Department of Macromolecular Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan.
Biomolecules
|February 26, 2025
概括
细菌的鞭毛运动器是细菌的鞭毛运动器.
科学领域:
- 细菌的运动性 细菌的运动性
- 蛋白质结构的分子机制
- 结构生物学是结构生物学.
背景情况:
- 细菌的鞭毛电机使用通过定子单元的离子流来驱动旋转.
- 定位器单元的定涉及B子单元与酸甘相互作用.
- 格拉姆阴性细菌改变N端螺旋以定,但格拉姆阳性机制不同.
研究的目的:
- 阐明定位器单元在阳性细菌 *Bacillus subtilis* 中固定的机制.
- 研究离子 (Na+) 在 MotS 蛋白的结构转变中的作用.
- 在不同的Na+度下确定关键的MotsS片段的晶体结构.
主要方法:
- 在高度和低度的Na+中,X射线晶体学以确定Mots$_{68-242}$的结构.
- 远紫外线循环二极化 (CD) 光谱分析蛋白质结构和形状变化.
- 在不同的离子条件下对野生类型和突变MotsS蛋白的生物化学分析.
主要成果:
- MotS$_{68-242}$的晶体结构在高度和低度的Na+中显示出不同的形状.
- 磁盘光谱学表明,在Mots$_{68-242}$的N终端无序区域中,存在一个Na+依赖的线圈螺旋过渡.
- 突变变种证实了特定区域在Na+依赖的结构变化中的作用.
结论:
- * Bacillus subtilis * MotS的周等离子域经历了Na+依赖的结构转变,用于定位器单元的定.
- 在Mots的N终端区域的线圈螺旋过渡对于固定定位器单元至关重要.
- 这项研究提出了一种新的机制,用于鞭毛电机定位器在格拉姆阳性细菌中固定.
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