High-Resolution Rotation Assay of the Bacterial Flagellar Motor Near Zero Loads Using a Mutant Having a Rod-Like Straight Hook
High-Resolution Rotation Assay of the Bacterial Flagellar Motor Near Zero Loads Using a Mutant Having a Rod-Like Straight Hook
复制标题
使用具有杆状直钩的突变体对接近零负载的细菌鞭毛马达进行高分辨率旋转测定
DOI：
10.1007/978-1-0716-3060-0_11
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发表时间：
2023
影响因子：
--
通讯作者：
Minamino Tohru
中科院分区：
文献类型：
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作者：
Nakamura Shuichi;Minamino Tohru
细菌鞭毛马达嵌入在细胞外膜内，并旋转长螺旋丝，其充当分子螺旋以推进细菌。鞭毛马达包括一个转子和十几个定子单元，将通过定子单元的离子通量转换为扭矩。然而，能量耦合机制尚未完全理解。旋转测量的各种方法已被开发，以了解鞭毛电机的旋转机制，但在最近的研究中最优选的方法是珠测定，它跟踪旋转的微米至亚微米珠连接到部分剪切的鞭毛丝在高的时间和空间分辨率。珠子试验使我们能够评估电机在大范围的外部负载下的旋转，但鞭毛轴向部分（例如钩和细丝）的弹性限制了时空分辨率。在这一章中，我们描述了一个珠测定优化的鞭毛电机动力学分析在近零负荷。
The bacterial flagellar motor is embedded within the cell envelop and rotates the long helical filament, which acts as a molecular screw to propel the bacterium. The flagellar motor comprises a rotor and a dozen stator units, converting ion flux through the stator unit into torque. However, the energy coupling mechanism has not been fully understood. Various methods for rotation measurement have been developed to understand the rotation mechanism of the flagellar motor, but the most preferred method in recent studies is a bead assay, which tracks the rotation of a micron to submicron bead attached to the partially sheared flagellar filament at high temporal and spatial resolutions. The bead assay allows us to assess the motor rotation over a wide range of external load, but the elasticity of the axial parts of the flagellum, such as the hook and filament, limits the spatiotemporal resolution. In this chapter, we describe a bead assay optimized for the analysis of the flagellar motor dynamics at near zero load.