Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions
Borrelia burgdorferi periplasmic flagella have both skeletal and motility functions
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DOI：
10.1073/pnas.200221797
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发表时间：
2000-09-26
影响因子：
11.1
通讯作者：
Charon, NW
中科院分区：
文献类型：
--
作者：
Motaleb, MA;Corum, L;Charon, NW
细菌的形状通常由细胞壁的肽聚糖层决定。在本文中，我们表明，莱姆病螺旋体伯氏疏螺旋体的形态是一个复杂的相互作用的结果之间的细胞圆柱体和内部周质鞭毛。a. burgdorferi具有一束7-11个螺旋形周质鞭毛，附着在细胞柱的每一端，并具有平波细胞形态。向后移动的传播波使这些细菌能够在低粘度介质和高粘度凝胶状介质中游泳。使用靶向诱变，我们失活的基因编码的主要周质鞭毛丝蛋白FlaB。由此产生的flaB突变体不仅是不动的，但杆状。Western blot分析表明FlaB不再合成，电子显微镜显示突变体完全缺乏周质鞭毛。用质子载体羰基氰化物-间氯苯腙中毒的野生型细胞保留了它们的平波形态，这表明周质鞭毛不需要为细胞提供能量来维持这种形状。我们的研究结果表明，周质鞭毛的A。burgdorferi有骨骼功能。这些细胞器动态地与杆状细胞柱相互作用，使细胞能够游动，并部分地赋予其平波形态。
Bacterial shape usually is dictated by the peptidoglycan layer of the cell wall. In this paper, we show that the morphology of the Lyme disease spirochete Borrelia burgdorferi is the result of a complex interaction between the cell cylinder and the internal periplasmic flagella. a. burgdorferi has a bundle of 7-11 helically shaped periplasmic flagella attached at each end of the cell cylinder and has a flat-wave cell morphology. Backward moving, propagating waves enable these bacteria to swim in both low viscosity media and highly viscous gel-like media. Using targeted mutagenesis, we inactivated the gene encoding the major periplasmic flagellar filament protein FlaB. The resulting flaB mutants not only were nonmotile, but were rod-shaped. Western blot analysis indicated that FlaB was no longer synthesized, and electron microscopy revealed that the mutants were completely deficient in periplasmic flagella. Wild-type cells poisoned with the protonophore carbonyl cyanide-m-chlorophenyl hydrazone retained their flat-wave morphology, indicating that the periplasmic flagella do not need to be energized for the cell to maintain this shape. Our results indicate that the periplasmic flagella of a. burgdorferi have a skeletal function. These organelles dynamically interact with the rod-shaped cell cylinder to enable the cell to swim, and to confer in part its flat-wave morphology.