The Mechanism of Energy Level Sensing in Escherichia coli

一个细胞的能级是由三个 相互转化的成分：ATP，质子动力， 电子传递链的氧化还原水平。 氧气出租车， 可氧化底物趋化性和趋光性都是 由能量水平的感应控制。 这项研究将 识别E的能量水平传感器。大肠杆菌，并建立 感知的主要机制。 arcB突变体不能显示O2- 趋化性和可氧化底物（脯氨酸）趋化性。 克隆的arcB 基因座将用于通过表达和 arcB产品的本地化。 通过比较细胞对CN的反应 和解偶联剂，其类似地降低PMF，但具有不同的 氧化还原状态的影响，将发现是否氧化还原 链组件或pmf本身立即负责 能级检测 对信息传递的理解 将通过分离arcB的假回复突变体来实现， 在che基因中作图。 这项研究将两个领域联系起来， 知识：代谢调节和行为，自arcB 控制着趋化性和氧依赖性转录。 极有 arcB（或同源化合物）可能另外是 对其他所谓的“依赖药物管理局”的情况负责 调节在各种细菌，以及在线粒体和 叶绿体 了解细菌细胞是如何 感知自己的能量水平，并利用这些信息来控制 行为 一种新型的传感器， 将在本研究中探索已知传感器。 校长 将阐明能级感测的机制。 因为它 线粒体和叶绿体可能“遗传”了 从细菌的能量水平传感器，这项研究可能会提供一个 研究高等生物行为的模型系统。

The energy level of a cell is determined by the state of three interconvertible components: ATP, the proton motive force, and the redox level of the electron transport chain. Oxygen taxis, oxidizable substrate taxis and phototaxis are all behaviors governed by sensing of the energy level. This research will identify the energy-level sensor of E. coli and establish the principal mechanism of sensing. An arcB mutant fails to show O2- taxis and oxidizable substrate (proline) taxis. A cloned arcB locus will be used to identify the sensor by expressing and localizing the arcB product. By comparing cell responses to CN and uncoupler that similarly decrease the pmf, but have different effects on the redox state, it will be found whether a redox chain component or pmf per se are immediately responsible for energy level sensing. Understanding of information transduction will be achieved by isolating pseudorevertants to arcB that will map in a che gene(s). This study bridges two fields of knowledge: metabolic regulation and behavior, since arcB controls both taxis and O2-dependent transcription. It is highly possible that arcB (or a homologous compound) is additionally responsible for other instances of so-called "pmf-dependent" regulation in various bacteria, as well as in mitochondria and chloroplasts. It is of fundamental significance to learn how the bacterial cell senses its own energy level and uses this information to control behavior. A new type of sensor which is substantially different from known sensors will be explored in this study. The principal mechanism of energy level sensing will be elucidated. Since it is possible that mitochondria and chloroplasts "inherited" the energy level sensor from bacteria, this research may provide a model system for studying behavior of higher organisms.