Delineation of unique flagellar proteins in spirochetes

螺旋体是一组研究较少的医学上有重要意义的细菌。螺旋体的运动性是由 周质鞭毛，驻留并在周质空间内旋转。这些细菌的能动性对 迄今为止研究过的所有致病螺旋体的毒力，包括伯氏疏螺旋体。而运动则扮演着这样的角色 作为一个至关重要的角色，我们对周质鞭毛的组装、运作或组织知之甚少 螺旋体。尽管周质鞭毛的许多成分在 模式生物肠沙门氏菌和大肠埃希氏菌的外鞭毛，一些独特的成分 周质鞭毛的位置明显区别于外部鞭毛。最重要的是，我们最近的研究 提供了第一个证据，证明了螺旋体特有的新成分，即周质环 对于鞭毛的组装和定向、这些细菌独特的形态和运动性是必不可少的。 然而，对编码周质环的基因或它们在任何 螺旋体。根据我们的初步数据，我们假设周质领由多个 新的螺旋体特异性蛋白质，这些蛋白质中的每一种在鞭毛组装中都发挥着不同的作用， 螺旋体具有独特的形态和运动性。为了解决这一假设，我们提出了两个具体目标。 目标1是鉴定组成大领子复合体的蛋白质，确定它们的天然细胞结构 并在伯氏杆菌中发挥作用。此外，为了扩大B.burgdorferi周质领研究的相关性， 我们建议确定这些新的鞭毛蛋白或它们的功能是否在其他螺旋体中保守。 目标1有望通过使用生物信息学、遗传学、各种生化分析和冷冻技术来实现。 电子断层摄影术。我们希望确定编码衣领复合体结构的蛋白质，它们的功能， 螺旋体的位置、结构和组装。提出了确定顺序装配的目标2 细胞被膜中周质领蛋白的相互作用和了解新的领蛋白之间的相互作用 与其他显著的鞭毛蛋白及其对周质所需扭矩增加的影响 鞭毛在粘性或复杂的介质中旋转，如哺乳动物组织。我们计划实现这一目标 目的应用各种突变、生化和冷冻电子断层扫描技术。我们希望能够理解 周质鞭毛在螺旋体中组装，并对伯氏杆菌产生整体影响。《知识》 从这个项目中获得的是理解小说的生物合成、组装和功能的基础 鞭毛蛋白不仅在伯氏杆菌和钩端螺旋体中存在，而且在其他具有医学意义的生物中也存在。 无法培养的螺旋体，如梅毒螺旋体。这些研究还可以导致在结构方面的应用- 基于药物设计，破坏发动机组装，从而阻止莱姆病和其他疾病的传播 由螺旋体传播的疾病。

Spirochetes are a group of poorly studied medically significant bacteria. The motility of spirochetes is driven by periplasmic flagella, which reside and rotate within the periplasmic space. These bacterial motility is crucial for virulence by all pathogenic spirochetes studied to-date including Borrelia burgdorferi. While motility plays such a vital role, we know very little about the periplasmic flagellar assembly, operation or organization in any spirochete. Although many components of the periplasmic flagellum have highly conserved counterparts in the external flagella from the model organisms Salmonella enterica and Escherichia coli, some unique components of the periplasmic flagella clearly distinguish them from external flagella. Most importantly, our recent studies have provided the first evidence that the novel spirochete-specific component known as the periplasmic collar is essential for flagellar assembly and orientation, the distinctive morphology and motility of these bacteria. However, very little is known about the genes encoding the periplasmic collar or their function in any spirochete. Based on our preliminary data, we hypothesize that the periplasmic collar is comprised of multiple novel spirochete-specific proteins, and that each of these proteins plays a distinct role in flagellar assembly, spirochetes distinctive morphology and motility. To address this hypothesis, we propose two specific aims. Aim 1 is to identify the proteins that make-up the large collar complex, determine their native cellular structure and function in B. burgdorferi. Moreover, to extend the relevance of B. burgdorferi periplasmic collar studies, we propose to determine if these novel flagellar proteins or their function is conserved in other spirochetes. Aim 1 is expected to be accomplished by using bioinformatics, genetics, various biochemical assays and cryo- electron tomography. We expect to identify the proteins encoding the collar complex structure, their function, location, structure, and assembly in the spirochetes. Aim 2 is proposed to determine the sequential assembly of the periplasmic collar proteins in the cell envelope and to understand the interactions of novel collar proteins with other prominent flagellar proteins and their impacts on increased torque required for the periplasmic flagella to rotate in viscous or complex medium such as the mammalian tissues. We plan to accomplish this aim using various mutational, biochemical, and cryo-electron tomography. We expect to understand how the periplasmic flagella are assembled in the spirochete and their overall impacts in B. burgdorferi. The knowledge gained from this project is fundamental to understand the biosynthesis, assembly, and function of the novel flagellar proteins not only in B. burgdorferi and Leptospira but also in other medically significant yet uncultivable spirochetes such as Treponema pallidum. These studies can also lead to applications in structure- based drug design to disrupt motor assembly, therefore blocking the spread of Lyme as well as other spirochete-borne diseases.