Formation and dynamics of interacting electron transport chains

相互作用电子传输链的形成和动力学

• 批准号: 299448403
• 负责人: Professor Dr. Johannes Gescher
• 金额: --
• 依托单位: Institut für Technische Mikrobiologie V-7
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/299448403?language=en
• 关键词: Formation; dynamics; interacting; electron; transport

It is the aim of this proposal to analyze the basis of periplasmic and outer membrane spanning electron transfer in the y-proteobacterium Shewanella oneidensis. S. oneidensis is so far the microorganism that shows the highest flexibility in terms of anaerobic electron acceptors, that can be used for respiration. Interestingly, almost all electron acceptors are reduced either in the periplasm or at the cell surface and the electron transfer to these acceptors is dependent on the activity of c-type cytochromes. A dynamic electron transfer network was evolved by the organism, in which the electron transfer chains are interconnected and produced simultaneously. We would like to understand the detailed mechanism of electron transport within this network via mutant analysis and concomitant measurement of electron transport rates in cell suspension and fast kinetic measurement experiments. Moreover, we would like to elucidate principles in the formation of an outer membrane protein complex that enables membrane spanning electron transport. The complex consists of an integral beta-barrel protein (MtrB) that connects a periplasmic (MtrA) and cell surface localized c-type cytochromes. Interestingly, we could show that MtrB is degraded by the periplasmic protease DegP in the absence of MtrA and it was suggested that MtrA is a specialized periplasmic chaperone that is necessary for transport of the unfolded beta-barrel protein through the periplasm. Furthermore, we could provide evidence that the fold of MtrB in the membrane varies in the presence and absence of MtrA, respectively. Via in vivo and in vitro experiments we aim to understand the detailed function of MtrA in formation and folding of MtrB.

这是本建议的目的是分析的周质和外膜跨越电子转移的Y-变形杆菌希瓦氏oneidensis的基础。S. oneidensis是迄今为止在可用于呼吸的厌氧电子受体方面显示出最高灵活性的微生物。有趣的是，几乎所有的电子受体都在周质或细胞表面被还原，电子转移到这些受体取决于c型细胞色素的活性。生物体进化出一个动态的电子传递网络，其中电子传递链相互连接并同时产生。我们希望通过突变体分析和细胞悬浮液中电子传递速率的伴随测量以及快速动力学测量实验来了解该网络中电子传递的详细机制。此外，我们想阐明的原则，形成一个外膜蛋白复合物，使跨膜电子传递。该复合物由连接周质（MtrA）和细胞表面定位的C型细胞色素的整合β-桶蛋白（MtrB）组成。有趣的是，我们可以表明，MtrB是由周质蛋白酶DegP降解的MtrA的情况下，它表明，MtrA是一个专门的周质伴侣是必要的运输未折叠的β-桶蛋白通过周质。此外，我们可以提供证据表明，MtrB在膜中的折叠在MtrA的存在和不存在下分别发生变化。通过体内和体外实验，我们的目的是了解MtrA的形成和折叠的MtrB的详细功能。