Moon Ki Hwan, Zhao Xiaowei, Manne Akarsh, Wang Juyu, Yu Zhou, Liu Jun, Motaleb Md A
Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Department of Pathology and Laboratory Medicine, University of Texas Health Science Center, Houston, TX, USA.
Mol Microbiol. 2016 Oct;102(2):336-348. doi: 10.1111/mmi.13463. Epub 2016 Aug 9.
Borrelia burgdorferi, the causative agent of Lyme disease, is a highly motile spirochete, and motility, which is provided by its periplasmic flagella, is critical for every part of the spirochete's enzootic life cycle. Unlike externally flagellated bacteria, spirochetes possess a unique periplasmic flagellar structure called the collar. This spirochete-specific novel component is linked to the flagellar basal body; however, nothing is known about the proteins encoding the collar or their function in any spirochete. To identify a collar protein and determine its function, we employed a comprehensive strategy that included genetic, biochemical, and microscopic analyses. We found that BB0286 (FlbB) is a novel flagellar motor protein, which is located around the flagellar basal body. Deletion of bb0286 has a profound effect on collar formation, assembly of other flagellar structures, morphology, and motility of the spirochete. Orientation of the flagella toward the cell body is critical for determination of wild-type spirochete's wave-like morphology and motility. Here, we provide the first evidence that FlbB is a key determinant of normal orientation of the flagella and collar assembly.
莱姆病的病原体伯氏疏螺旋体是一种高度能动的螺旋体，其周质鞭毛赋予的运动能力对于该螺旋体在动物间传播的生命周期的各个环节都至关重要。与外部有鞭毛的细菌不同，螺旋体拥有一种独特的周质鞭毛结构，称为套环。这种螺旋体特有的新成分与鞭毛基体相连；然而，对于编码套环的蛋白质或其在任何螺旋体中的功能却一无所知。为了鉴定一种套环蛋白并确定其功能，我们采用了一种综合策略，包括遗传、生化和显微镜分析。我们发现BB0286（FlbB）是一种新的鞭毛运动蛋白，位于鞭毛基体周围。缺失bb0286对套环形成、其他鞭毛结构的组装、螺旋体的形态和运动能力有深远影响。鞭毛朝向细胞体的方向对于确定野生型螺旋体的波浪状形态和运动能力至关重要。在此，我们提供了首个证据，证明FlbB是鞭毛正常方向和套环组装的关键决定因素。
