Structural and functional analysis of NDH-1 supercomplexes

NDH-1 超级复合物的结构和功能分析

• 批准号: 524822763
• 负责人: Professor Dr. Marc Nowaczyk
• 金额: --
• 依托单位: Zentrum für Synthetische Mikrobiologie (SYNMIKRO)
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/524822763?language=en
• 关键词: Structural; functional; analysis; NDH; supercomplexes

Membrane protein complexes play a crucial role in bioenergetics, particularly in photosynthetic organisms. They are responsible for the light-to-chemical energy conversion in the primary reactions of photosynthesis, thereby driving the energy gradient that promotes and sustains almost all life on our planet. In this fundamental process, they combine the light-driven transport of electrons with the vectorial transport of protons across a membrane. We are particularly interested in one type of these molecular machines, complex I (aka NDH-1), which is part of photosynthetic as well as respiratory electron transport chains. It combines electron transfer from ferredoxin (Fd) to plastoquinone with the transfer of protons across the thylakoid membrane in a yet unknown fashion and many questions concerning their precise molecular function remain unanswered due to the lack of structure-function based mutagenesis studies in vitro and in vivo. In principle, as highly efficient proton pumps, they could contribute to light-driven proton motive force (PMF) formation substantially by accepting electrons from photosystem I (PSI) via Fd in cyclic electron transport, but their role in vivo is rather unclear. It is known from land plants that PSI and NDH-1 form a supercomplex, however current structural models are incomplete and miss the Fd interacting subunits. Moreover, in cyanobacteria supercomplex formation of NDH-1 with PSI and CpcG2-phycobilisomes or with H2ase/Diaphorase as an alternative pathway is still elusive. The project will provide novel molecular insights into NDH-1 function and its integration into the dynamic electron transport network of the cell based on our recent advances in structural analysis of the cyanobacterial complex. Specifically, we will focus on supercomplex formation with PSI and with H2ase/Diaphorase to understand its role in PMF formation. Cyanobacterial supercomplexes will be targeted in the model organisms Synechocystis sp. PCC 6803 and the filamentous, diazotrophic cyanobacterium Anabaena sp. PCC 7120, which will be compared to the land plant supercomplex form the bryophyte P. patens, a genetically accessible system that allows comparatively easy upscaling of biomass production.

膜蛋白复合物在生物能学中起着至关重要的作用，尤其是在光合生物中。它们负责光合作用的主要反应中的光到化学能量转换，从而推动了促进和维持我们地球上几乎所有生命的能量梯度。在这个基本过程中，它们将电子的轻度运输与质子跨膜的矢量传输相结合。我们对一种类型的分子机器，复杂的I（又名NDH-1）特别感兴趣，它是光合作用和呼吸电子传输链的一部分。它以一种未知的方式结合了从铁蛋白（FD）到质喹酮与质子在类囊体膜中转移的电子转移，并且由于缺乏基于结构功能的诱变研究，其精确分子功能的许多问题仍然无法得到交流。原则上，作为高效的质子泵，它们可以通过在环环电子传输中通过FD接受来自光系统I（PSI）的电子（PSI）的电子形成，从而有助于发光的质子动力（PMF）形成，但是它们在Vivo中的作用尚不清楚。从陆地植物中知道，PSI和NDH-1形成了超复合物，但是当前的结构模型不完整并且错过了FD相互作用的亚基。此外，在PSI和CPCG2-Phycobilisomes或H2ase/diaphorase septerative途径中，NDH-1的蓝细菌超复合形成仍然难以捉摸。该项目将根据我们在蓝细菌复合物的结构分析方面的最新进展，对NDH-1功能及其在细胞的动态电子传输网络中的整合提供新的分子见解。具体而言，我们将专注于与PSI和H2ase/diaphorase一起使用超复合形成，以了解其在PMF形成中的作用。蓝细菌超复合物将针对模型生物属性生物体。 PCC 6803和丝状，重18zozotrophic Cyanobacterium anabaena sp。 PCC 7120，将与陆地植物超复合物进行比较，形成了Bryophyte P. Patens，这是一种遗传上可访问的系统，可以使生物量生产的相对简单地升级。