MOLECULAR GENETICS OF THE CYTOCHROME BC1 COMPLEX

细胞色素 BC1 复合物的分子遗传学

• 批准号: 6018687
• 负责人: M. FEVZI DALDAL
• 金额: $ 24.19万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-12-01 至 2001-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6018687
• 关键词: Rhodospirillales; bacterial genetics; bioenergetics; cytochrome c; cytochrome oxidase; enzyme complex; enzyme mechanism; gene mutation; nucleic acid sequence; protein biosynthesis; protein engineering; protein purification; protein structure function; site directed mutagenesis

DESCRIPTION: A vital characteristic of living systems is their ability to perform efficient energy conversion. Biological energy transduction (ET) is the ensemble of pathways necessary for cellular energy (ATP) production, which is essential for many cellular functions, including macromolecular biosynthesis, solute transport, signal transduction, chemotaxis, phototaxis, and thermogenesis. The long term goal of this project is to define the cytochrome (cyt) components of the ET pathways, and to understand their structure, mechanism of function and biogenesis (i.e., assembly and regulation). Facultative phototrophic bacteria (e.g., Rhodobacter species) provide an excellent model system for eukaryotic organelles. The ET complexes are widespread among living organisms, and their improper function leads to devastating neuromuscular and mitochondrial diseases in humans, and low crop yields in plants. The project will continue biochemical and molecular genetics of ET complexes, focusing on the structure, function, and biogenesis of membrane-bound, multisubunit cyt c complexes (i.e., the ubihydroquinone:cyt c oxidoreductase, or the bc1 complex, and the recently discovered cyt cb oxidase). The specific aims include the isolation and characterization of mutants of the FeS protein ( a subunit of the bc1 complex) and analysis of their revertants to better understand the role this subunit plays in quinol oxidation; purification and characterization of the FeS protein and the two subunit bc1 subcomplex of R. capsulatus; engineering of structurally simpler bc1 complexes to correlate structural flexibility and functional similarities between oxidoreductases; isolation and characterization of new mutants affecting the biogenesis of multisubunit cyt c complexes and incorporation of their heme and iron-sulfur prosthetic groups; and genetic analyses of biogenesis mutants and determination of cellular locations of their gene products. These studies will increase our understanding of the structure and mechanism of function of the bc1 complex, and provide important insights into the biogenesis of membrane-bound multisubunit cyt c complexes that operate during cellular ET, an important biological process which is far from being completely understood, even in bacteria. Insights gained in this simpler system are generally applicable to the structurally more complex and yet functionally similar organelle-derived ET complexes, and are important for the elucidation of the molecular basis of mitochondrial diseases and aging.

描述：生命系统的一个重要特征是它们有能力 进行高效的能量转换。生物能量转导(ET) 细胞能量(ATP)产生所需的一系列途径， 它对许多细胞功能是必不可少的，包括大分子 生物合成，溶质运输，信号转导，趋化，趋光， 和生热作用。该项目的长期目标是定义 ET途径的细胞色素(Cyt)组分，并了解其 结构、功能机制和生物发生(即组装和 条例)。兼性光养细菌(例如，红细菌) 为真核细胞器研究提供了一个良好的模型体系。外星人 复合体在生物体中广泛存在，其不适当的功能 导致人类患上毁灭性的神经肌肉和线粒体疾病 作物产量低。该项目将继续进行生化和 ET复合体的分子遗传学，重点研究ET复合体的结构、功能和 膜结合的多亚单位细胞色素C复合体的生物发生 泛氢对苯二酚：细胞色素c氧化还原酶，或Bc1复合体，以及最近的 发现了Cyt CB氧化酶)。具体目标包括隔离和隔离 FES蛋白(Bc1亚基)突变体的鉴定 Complex)，并对它们的返回体进行分析，以更好地理解这一作用 亚基在对苯二酚氧化中的作用；纯化和表征 FeS蛋白和双亚单位Bc1亚基复合体；工程 结构更简单的Bc1复合体，以关联结构灵活性 和氧化还原酶之间的功能相似性；分离和 影响多亚基Cyt生物发生的新突变体的特性 C络合物及其血红素和铁硫假体的掺入 群；生物发生突变体的遗传分析和测定 他们的基因产物的细胞位置。这些研究将增加我们的 了解Bc1复合体的结构和功能机制， 为膜结合蛋白的生物发生机制提供了重要的见解 在细胞ET过程中工作的多亚单位Cyt c复合体，是一个重要的 生物过程还远未完全被理解，即使在 细菌。在这个更简单的系统中获得的见解通常适用于 到结构更复杂但功能相似的 细胞器衍生的ET复合体，对于阐明 线粒体疾病和衰老的分子基础。