BIOCHEMISTRY OF MEMBRANE AND CATALYTIC PROTEINS

膜和催化蛋白的生物化学

• 批准号: 3269830
• 负责人: BRUCE A MC FADDEN
• 金额: $ 20.05万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1976
• 资助国家: 美国
• 起止时间: 1976-06-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3269830
• 关键词: Cyanophyta; DNA replication; Rhodospirillum; X ray crystallography; binding proteins; carbon dioxide fixation; catalyst; cell membrane; crosslink; cytoplasm; decarboxylases; electron microscopy; enzyme mechanism; genetic manipulation; immunologic assay /test; membrane proteins; microorganism metabolism; mutant; northern blottings; nuclear magnetic resonance spectroscopy; oxygenases; phosphoproteins; photosynthesis; photosynthetic bacteria; protein biosynthesis; protein sequence; protein structure function

One major objective is to elucidate fundamental relationships between the structure and function of the enzyme ribulose bisphosphate carboxyase/oxygenase (RuBisCO) which catalyzes primary carbon dioxide fixation in Nature and is one of the most abundant proteins on earth. This protein, which consists of large (L) and small (S) subunits in most species, undergoes carbamylation to a catalytically active form which can then catalyze either carboxylative or oxygenolytic cleavage of ribulose bisphosphate. The latter initiates photorespiration, a process which opposes growth on carbon dioxide. The long-range objective is to test the feasibility of enhancing photosynthesis and/or decreasing photorespiration by altering RuBisCO. Attendant changes in autotrophic growth rate may be striking and may ultimately be reflected in increased plant productivity. The emphasis for many years in this laboratory has been on RuBisCO from bacteria. Bacteria not only provide enzymes that vary in quaternary structure (some lacking the S subunit) but some are excellent modils for the plant enzyme. A better understanding of the structure and function of proteins (such as RuBisCO) may assist in the cure or arrest of human diseases which are frequently due to the production of altered proteins. In the current project period, it has been discovered that RuBisCO is anchored to the cytoplasmic membrane via S subunits in one photosynthetic bacterium. The biological significance of this attachment will be investigated. More specifically the structure and function of RuBisCO will be investigated in terms of: (a) the function of S subunits including the domain(s) for membrane attachment and (b) the function of L subunits. These investigations will include chemical cross-linking studies and in vitro mutagenesis of L and S subunit genes and will focus on one of the cyanobacteria, Anacystis nidulans. They will also include studies of the modification of RuBisCO by transglutaminase to assess the biological significance of this modification. Parallel studies of the replication of foreign DNA in cyanobacteria will be conducted. Hence, the feasibility of incorporating interesting genes (such as L and S subunit gene modifications) into cyanobacteria will be examined. Results will shed light on the origin of DNA replication in cyanobacteria and provide a basis for comparison with other bacteria including pathogens.

一个主要目标是阐明 双磷酸酶的结构和功能 羧化酶/氧合酶（Rubisco），催化原代二氧化碳 自然界是固定的，是地球上最丰富的蛋白质之一。 该蛋白质由大多数大多数（L）和小亚基组成 物种，将甲酰胺化成催化活性形式，可以 然后催化核糖的羧化或氧化裂解 双磷酸盐。 后者启动了光孔刺激，这一过程 反对二氧化碳的生长。远程目标是测试 增强光合作用和/或减少的可行性 通过改变rubisco的光振动。 随之而来的自养的变化 增长率可能会引人注目，最终可能反映在增加 植物生产力。 这个实验室多年来的重点 从细菌上使用Rubisco。 细菌不仅提供酶 在第四纪结构上有所不同（有些缺乏S亚基），但有些是 植物酶的极好模质。更好地理解 蛋白质的结构和功能（例如Rubisco）可能有助于 治愈或逮捕人类疾病，这些疾病经常是由于 产生改变的蛋白质。 在当前的项目期间，已经发现Rubisco是 通过一个光合作用的S亚基锚定在细胞质膜上 细菌。 该附件的生物学意义将是 调查。 更具体地说是Rubisco的结构和功能 将根据以下方面进行研究：（a）S亚基的功能 包括用于膜附着的域和（b）的功能 l亚基。 这些调查将包括化学交联 L和S亚基基因的研究和体外诱变，将集中 在一种蓝细菌中，Anacystis nidulans。 他们还将包括 通过转谷氨酰胺酶对Rubisco修饰的研究以评估 这种修饰的生物学意义。 平行研究 将进行蓝细菌中外国DNA的复制。因此， 合并有趣基因的可行性（例如L和S亚基 将检查基因修饰）将检查成蓝细菌。 结果将 阐明蓝细菌中DNA复制的起源，并提供 与包括病原体在内的其他细菌进行比较的基础。