MOLECULAR BASIS OF BACTERIAL MOTILITY

细菌运动的分子基础

• 批准号: 7601255
• 负责人: ANTON ARKHIPOV
• 金额: $ 4.13万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7601255
• 关键词: Bacteria; Cells; Computer Retrieval of Information on Scientific Projects Database; Filament; Flagella; Funding; Grant; Hand; Helix (Snails); Individual; Institution; Joints; Length; Liquid substance; Molecular; Motor; Proteins; Research; Research Personnel; Resources; Rotation; Running; Shapes; Slide; Solvents; Source; Structure; Torque; United States National Institutes of Health; Walking; Work; base; cell motility; computer studies; ear helix; kinetosome

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many types of bacteria propel themselves through liquid media using whip-like structures known as flagella (http://www.ks.uiuc.edu/Research/flagellum/). The bacterial flagellum is a huge (several micrometers long, 20 nm wide), multiprotein assembly built of three domains: a basal body, acting as a motor; a hook, acting as a joint; and a filament, which makes up the bulk of the length of the flagellum and interacts with solvent to propel the bacterium. Depending on the direction of the torque applied by the basal body, the filament assumes different helical shapes. Under counter-clockwise rotation (as viewed from the exterior of the cell), several flagella form a single helical bundle which propels the cell along a straight line, referred to as running mode [1]. Under clockwise rotation, the individual flagella dissociate from the bundle and form separate right-handed helices, causing the cell to tumble. Varying the duration of running and tumbling, bacteria can move up or down a gradient of an attractant or repellent by a biased random walk. One of the unresolved questions about the flagellum is how the reversal of torque applied by the motor results in a switching between the helical shapes of the filament. This switching is a result of polymorphic transitions in the filament, when individual protein units slide against each other [2], but its molecular mechanism remains poorly understood despite extensive experimental work [3, 2, 4] and a recent computational study [5].

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 许多类型的细菌使用称为鞭毛的鞭子样结构（http://www.ks.uiuc.edu/research/flagellum/）通过液体培养基推动自己。 细菌鞭毛是一个巨大的（几微米长，宽20 nm），由三个结构域建造的多蛋白组件：一个基体，充当电动机；钩子，充当关节；和细丝，构成了鞭毛的大部分长度并与溶剂相互作用以推动细菌。 根据基体施加的扭矩的方向，细丝采用不同的螺旋形状。 在逆时针旋转（从单元的外部看）下，几个鞭毛形成一个单个螺旋束，该螺旋束沿直线推动单元，称为运行模式[1]。在顺时针旋转下，单个鞭毛与束分离并形成单独的右螺旋螺旋，从而导致细胞滚滚。改变跑步和翻滚的持续时间，细菌可以通过偏见的随机行走向上或向下移动吸引剂或驱虫剂的梯度。 关于鞭毛的尚未解决的问题之一是，电动机施加的扭矩逆转如何导致细丝的螺旋形形状之间的切换。 当单个蛋白质单元相互对抗时，这种切换是丝中多态性转变的结果[2]，但是尽管实验性广泛[3，2，4]，但其分子机制和一项最近的计算研究[5] [5]。