Behavioral responses of Escherichia coli to changes in redox potential
Behavioral responses of Escherichia coli to changes in redox potential
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DOI：
10.1073/pnas.93.19.10084
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发表时间：
1996-09-17
影响因子：
11.1
通讯作者：
Taylor, BL
中科院分区：
文献类型：
--
作者：
Bespalov, VA;Zhulin, IB;Taylor, BL
大肠杆菌感受到周围环境的氧化还原状态，它们游向具有优先还原电位的生态位。在对苯醌/对苯醌醇的空间氧化还原梯度中，E.大肠杆菌细胞迁移形成一条清晰的条带，从条带两侧游出的细菌翻滚并回到条带所在的优选条件。这种行为反应被称为氧化还原趋化性，引起氧化还原趋化性的氧化还原分子，如取代的醌，与细菌的电子传递系统相互作用，从而改变电子传递和质子动力。行为反应的大小取决于化学效应物的还原电位。Tsr、Tar、Trg、Tap和CheR蛋白在趋化性中起作用，但对氧化还原趋化性不是必需的。一个切布突变体有反转的反应，在氧化还原的出租车，如前所述，在需氧性，提出了一个模型，其中的氧化还原效应分子扰动的电子传递系统，和一个未知的传感器在膜检测质子动力或电子传递系统的氧化还原状态的变化，并将此信息转换成一个信号，调节磷酸化的CheA蛋白。氧化还原趋化性可能在自然环境中细菌物种的分布中起重要作用。
Escherichia coli bacteria sensed the redox state in their surroundings and they swam to a niche that had a preferred reduction potential. In a spatial redox gradient of benzoquinone/benzoquinol, E. coli cells migrated to form a sharply defined band, Bacteria swimming out of either face of the band tumbled and returned to the preferred conditions at the site of the band. This behavioral response was named redox taxis, Redox molecules, such as substituted quinones, that elicited redox taxis, interact with the bacterial electron transport system, thereby altering electron transport and the proton motive force. The magnitude of the behavioral response was dependent on the reduction potential of the chemoeffector. The Tsr, Tar, Trg, Tap, and CheR proteins, which have a role in chemotaxis, were not essential for redox taxis. A cheB mutant had inverted responses in redox taxis, as previously demonstrated in aerotaxis, A model is proposed in which a redox effector molecule perturbs the electron transport system, and an unknown sensor in the membrane detects changes in the proton motive force or the redox status of the electron transport system, and transduces this information into a signal that regulates phosphorylation of the CheA protein. A similar mechanism has been proposed for aerotaxis, Redox taxis may play an important role in the distribution of bacterial species in natural environments.