Structure and Function of the proton-turbine of the ATP-Synthase

描述(申请人提供)：能量转导中最重要的蛋白质之一是三磷酸腺苷合成酶(FOF1)。这种膜结合的大型蛋白质复合体存在于几乎所有的生物体中，对地球上所有高等生命都是必不可少的，包括人类。该酶在功能、组装和降解途径上的轻微缺陷在巴顿病、阿尔茨海默病和视网膜色素变性综合征等严重疾病中发挥着重要作用。此外，人类线粒体ATP合酶受到高度调控，以响应细胞的能量需求。本项目的目的是揭示该酶的结构和催化机理。ATP合成酶作为一种分子(纳米)马达，在质子或钠离子的跨膜电化学势的驱动下，催化ADP和PI合成ATP。该酶复合体由两个不同的结构和功能域组成：膜内质子转运系统(FO部分)，它在结构上至少由两个“柄”连接到膜外域(F1部分)，后者又包含核苷酸结合部位。虽然膜外源性F1部分和离子传导FO部分的个别蛋白质亚基的结构已经被X射线结构晶体学所确定，但对于这种偶联机制的分子阐明仍然受制于关于完整的ATP合成酶和膜内质子转运机制的结构方面的信息。本项目的目标是确定三磷酸腺苷合成酶的质子涡轮结构，并揭示质子转移和三磷酸腺苷合成之间的耦合机制。该项目旨在结晶完整的ATP合成酶、质子传导的FO部分以及该酶的C-环转子，该酶的低聚状态在不同的生物体中是不同的。这些晶体将用于通过X射线结晶学确定蛋白质复合体的结构。这些结构信息将为发现酶催化循环中的动态能量耦合机制奠定基础。

DESCRIPTION (provided by applicant): One of the most important proteins in energy transduction is the ATP-Synthase (FOF1). This membrane- bound large protein complex is present in nearly all organisms and is essential for all higher life on earth, including humans. Slight defects in function, assembly and the degradation pathways of the enzyme play important roles in severe diseases such as the Batten's disease, Alzheimer's disease and the Retinitis Pigmentosa Syndrome. Furthermore, human mitochondrial ATP Synthase is highly regulated in response to cellular energy needs. The aim of this project is to unravel the structure and catalytic mechanism of this enzyme. The ATP Synthase functions as a molecular (nano) motor, thereby catalyzing the synthesis of ATP from ADP and Pi driven by a transmembrane electrochemical potential of protons or sodium ions. The enzyme complex consists of two distinct structural and functional domains: A membrane intrinsic proton translocation system (the FO part), which is structurally connected by at least two "stalks" to the membrane extrinsic domain (the F1 part), which in turn harbors the nucleotide binding sites. While several structures of the membrane extrinsic F1 part and individual protein subunits of the ion conduction FO part have been determined by X-ray structure crystallography, the molecular elucidation of the coupling mechanism still suffers from the lack of information on the structure of the complete intact ATP Synthase and the membrane intrinsic proton translocation machinery. The goal of this project is to determine the structure of proton turbine of the ATP-Synthase and discover the mechanism of the coupling between proton transfer and ATP-synthesis. The project aims to crystallize the intact ATP Synthase, the proton conducting FO part as well as the c-ring rotor of the enzyme, which differs in its oligomeric state between different organisms. The crystals will be used to determine the structure of the protein complexes by X-ray crystallography. The structural information will form the basis for the discovery of the mechanism of the dynamic energy coupling in the catalytic cycle of the enzyme.