Assembly of the membrane-bound FeS centre of the Na+-translocating NQR

铁是生命的基本元素，参与许多细胞反应。在与硫的配合物中，两个或两个以上的铁原子可以形成铁-硫簇，促进许多不同的酶促反应。在呼吸链中，许多酶依靠FeS中心催化氧化还原驱动的质子或Na+运输。通常，FeS中心与呼吸酶的外周部分结合，但Na+易位NADH：醌氧化还原酶（NQR）在复合物的膜部分结合了一个前所未有的FeS簇。NQR是一种呼吸Na+泵，存在于许多革兰氏阴性细菌中，包括致病性霍乱弧菌。在这个合作研究项目中，将使用微生物学、生化和生物物理技术研究这种新型膜结合的NQR FeS簇的性质和组装。先前的结果表明，团簇的结扎不寻常，这将通过改进的全息nqr晶体的x射线晶体学结构测定来研究。此外，我们将通过研究FeS载体蛋白NqrM的结构和功能来解决FeS簇插入NQR的途径。我们的目标是完全重建到NQR中新型FeS中心的铁硫传递途径，并了解该膜结合的FeS中心在NQR氧化还原驱动的Na+运输中的催化作用。

Iron is an essential element of life and participates in many cellular reactions. In complex with sulfur, two or more Fe atoms can form iron-sulfur clusters which facilitate many different enzymatic reactions. In the respiratory chain, many enzymes rely on FeS centers to catalyse redox-driven proton or Na+ transport. Typically, the FeS centers are bound to the peripheral part of the respiratory enzyme, but the Na+ -translocating NADH:quinone oxidoreductase (NQR) harbors an unprecedented FeS cluster bound within the membrane part of the complex. The NQR is a respiratory Na+ pump found in many gram-negative bacteria, including pathogenic Vibrio cholerae. In this collaborative research project, the properties and the assembly of this novel, membrane-bound FeS cluster of NQR will be studied using microbiological, biochemical and biophysical techniques. Previous results suggested an unusual ligation of the cluster which will be studied by X-ray crystallographic structure determination of improved crystals of holo-NQR. In addition, we will address the pathway of insertion of the FeS cluster to NQR by studying the structure and function of the FeS carrier protein NqrM. Our goals are the complete reconstruction of the iron-sulfur delivery pathway to the novel FeS center in NQR, and an understanding of the catalytic role of this membrane-bound FeS center in redox-driven Na+ -transport by NQR.