Funktion des Fumaratsensors DcuS von Escherichia coli in vivo und in vitro

在兼性厌氧大肠杆菌的富马酸传感器DcuSR已被确定，这代表了从有氧到无氧呼吸的开关的转录调节。DcuSR是由膜感受器（DcuS）和细胞质调节器（DcuR）组成的双组分调节系统。尽管这种类型的传感器在细菌中的意义和流行，但信号识别和转导的机制是未知的。周质结构域的结构测定正在进行中（合作AG Griesinger）。该提案的目的是研究从周质到DcuS膜结构域的信号转导所需的反应。DcuS的周质和膜结构域是必不可少的信号转导将被确定。结构域及其功能将在分离和重构的蛋白质中进行生物化学表征，并通过分子生物学方法在体内进行表征。这些功能研究，结合配体结合结构域的第一个结构信息，应该提高我们对双组分传感器信号转导的理解（参见Unden/Griesinger/Baldus的随附提案“DcuS结构”）。

In the facultative anaerobic Escherichia coli the fumarate sensor DcuSR has been identified, which represents a transcriptional regulator for the switch from aerobic to anaerobic respiration. DcuSR is a two-component regulatory system consisting of membraneous sensor (DcuS) and a cytoplasmic regulator (DcuR). In spite of the significance and prevalence of sensors of this type in bacteria, is the mechanism of signal recognition and transduction is unknown. Structure determination of the periplasmic domain is in progress (cooperation AG Griesinger). The aim of the proposal is the study of reactions which are required for the signal transduction from the periplasm to the membrane domain of DcuS. Periplasmic and membraneous domains of DcuS which are essential for signal transduction will be identified. The domains and their function will be characterised biochemically in the isolated and reconstituted protein, and in vivo by molecular biological methods. These functional studies, combined with the first strutural informations on the ligand binding domain, should improve our understanding of signal transduction by two-component sensors (see accompanying proposal "DcuS structure" by Unden/Griesinger/Baldus).