Repurposing a chemosensory macromolecular machine
Repurposing a chemosensory macromolecular machine
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DOI：
10.1038/s41467-020-15736-5
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发表时间：
2020-04-27
影响因子：
16.6
通讯作者：
Jensen, Grant J.
中科院分区：
文献类型：
--
作者：
Ortega, Davi R.;Yang, Wen;Jensen, Grant J.
复杂的多组件大分子机器是如何进化的仍然知之甚少。在这里，我们揭示了控制大肠杆菌鞭毛运动的化学感应机制的进化起源。我们首先鉴定了霍乱弧菌、铜绿假单胞菌、奥奈德希瓦氏菌和嗜碱甲基微生物中仍然存在的祖先形式，通过电子冷冻断层扫描来表征它们的结构，并找到它们在应激反应途径中发挥作用的证据。利用生物信息学，我们通过伽玛变形菌追踪系统的进化，查明导致现在在大肠杆菌中看到的机器的关键进化事件。我们的结果表明，具有不同输入和输出的两个古代化学感应系统（F6和F7）同时存在，其中一个（F7）最终接管了另一个（F6）的输入和输出，而后者随后消失了。细菌化学感应系统分为 17 个鞭毛类 (F1-17)。在这里，作者利用电子冷冻断层扫描和比较基因组学来表征γ-变形菌中的化学感应阵列，并鉴定出结构独特的 F7 形式，该形式在其进化过程中被重新用于不同的生物学作用。
How complex, multi-component macromolecular machines evolved remains poorly understood. Here we reveal the evolutionary origins of the chemosensory machinery that controls flagellar motility in Escherichia coli. We first identify ancestral forms still present in Vibrio cholerae, Pseudomonas aeruginosa, Shewanella oneidensis and Methylomicrobium alcaliphilum, characterizing their structures by electron cryotomography and finding evidence that they function in a stress response pathway. Using bioinformatics, we trace the evolution of the system through gamma -Proteobacteria, pinpointing key evolutionary events that led to the machine now seen in E. coli. Our results suggest that two ancient chemosensory systems with different inputs and outputs (F6 and F7) existed contemporaneously, with one (F7) ultimately taking over the inputs and outputs of the other (F6), which was subsequently lost. Bacterial chemosensory systems are grouped into 17 flagellar classes (F1-17). Here the authors employ electron cryotomography and comparative genomics to characterise the chemosensory arrays in gamma -proteobacteria and identify a structural distinct form of F7 that was repurposed to a different biological role over the course of its evolution.