Structure and regulation of the ATP synthase

描述(申请人提供)：本项目的长期目标是了解ATP合成酶的结构/功能关系，因为它与ATP合成酶的机制有关。这在心脏组织中尤其重要，因为在有氧条件下产生的ATP中，ATP合成酶占了大部分。此外，心脏中的三磷酸腺苷合成酶的调节已被证明发生在缺血条件下。最近，在一项合作研究中，我们获得了酵母F1 ATPase的3.0-3.3A电子密度图。这一重大进步现在允许我们使用酵母遗传学和X射线结晶学的全部工具来提问和回答问题。这项建议中的研究部分地调查了编码线粒体ATP合成酶亚单位的基因突变对ATP合成酶结构和功能的分子影响。这项研究的第一个目的是检验一种假设，即在缺乏关键亚基的情况下，ATP合成酶的组装可以发生，由此产生的复合体负责线粒体的解偶联。第二个目的是测试一类突变机制的假说，MGI是从ATP合成酶的亚基中分离出来的。第三个目标是利用X射线结晶学获得含有MGI突变的F1-ATPase的高分辨率结构。第四个也是最后一个目标将检验这样一个假设，即ATP合成酶的天然抑制剂阻止伽马亚基的单向旋转。这些实验将进一步了解ATP合成酶的结构和功能，也将提供关于ATP合成酶亚单位突变的功能后果的重要信息。最终，这个项目将提供关于ATP合成酶的调节以及这种调节对细胞的整体能力的重要性的关键信息，以提供组织和有机体在正常和疾病状态下所需的足够的能量。

DESCRIPTION (provided by applicant): The long-term goal of this project is to gain an understanding on the structure/function relationship of the ATP synthase as it relates to mechanism of the ATP synthase. This is particularly important in cardiac tissue since the ATP synthase accounts for majority of ATP made under aerobic conditions. Furthermore, regulation of the ATP synthase in heart has been shown to occur under ischemic conditions. Recently, in a collaborative study, we were able to obtain a 3.0-3.3 A electron density map of the yeast F1 ATPase. This major advance now allows us to ask and answer questions using the full tools of yeast genetics and x-ray crystallography. The studies in this proposal, in part, investigate the molecular impact of mutations in genes encoding subunits of the mitochondrial ATP synthase on the structure and function of the ATP synthase. The first aim of this study tests a hypothesis that assembly of ATP synthase can occur in the absence of key subunits and the resulting complex is responsible of the uncoupling of the mitochondria. The second aim tests the hypothesis for the mechanism of a class of mutations, mgi, isolated in subunits of the ATP synthase. The third aim will utilize x-ray crystallography to obtain a high-resolution structure of the F1-ATPase containing the mgi mutations. The fourth and final aim will test the hypothesis that the natural inhibitor of the ATP synthase prevents the unidirectional rotation of the gamma-subunit. These experiments will provide a further understanding on the structure and function of the ATP synthase, but will also provide important information on the functional consequences of mutations in subunits of the ATP synthase. Ultimately, this project will provide critical information on the regulation of the ATP synthase and the importance of this regulation on the overall capabilities of the cell to provide enough energy as demanded by tissue and organism in both the normal and disease states.