Structural Studies of Fe:S Proteins: Nitrogenase, Rubredoxin and Ferredoxin

Fe:S 蛋白质的结构研究：固氮酶、红氧还蛋白和铁氧还蛋白

• 批准号: 9118689
• 负责人: Douglas Rees
• 金额: $ 63.5万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 1998-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9118689&HistoricalAwards=false
• 关键词: Structural; Studies; Fe; Proteins; Nitrogenase

Iron-sulfur (Fe:S) centers in proteins exhibit a diverse range of structures and functional properties. X-ray diffraction methods will be used to determine the three-dimensional structures of three Fe:S proteins involved in electron transfer reactions: the nitrogenase molybdenum-iron protein from Azotobacter vinelandii and the rubredoxin and ferredoxin from the hyperthermophile Pyrococcus furiosis. The crystallographic structures will permit an evaluation of the roles of the polypeptide and iron-sulfur centers in controlling the redox properties and electron transfer mechanisms of these proteins. The specific structural objectives of this proposal are: Nitrogenase molybdenum-iron protein. The molybdenum iron (MoFe-) protein component of nitrogenase contains the site of substrate reduction, an iron-sulfur-molybdenum cofactor of presently unknown structure. The functional roles of the clusters and protein will be addressed by crystallographic studies to at least 2.5A resolution of the A. vinelandii MoFe-protein in the presence and absence of bound ligands (inhibitor and nucleotides) and in different oxidation states: mutant MoFe-proteins; and structures of alternative nitrogenase proteins related to MoFe-protein. Thermostable rubredoxin and ferredoxin. The archaebacterium Pyrococcus furiosis is a hyperthermophile that grows at 1000C. Crystallographic structures of the rubredoxin (refined to at least 0.96A resolution) and ferredoxin from this organism will not only define the details of the protein-Fe:S center interactions, but will also provide a structural framework for characterizing the thermostability of these proteins.

蛋白质中的铁硫（Fe:S）中心具有多种结构和功能特性。x射线衍射方法将用于确定参与电子转移反应的三种Fe:S蛋白的三维结构：来自固氮菌vinelandii的氮氧化酶钼铁蛋白和来自超嗜热性肺炎热球菌的红氧还蛋白和铁氧还蛋白。晶体结构将允许评价多肽和铁硫中心在控制这些蛋白质的氧化还原性质和电子转移机制中的作用。本方案的具体结构目标为：氮酶钼铁蛋白。氮酶的钼铁（MoFe-）蛋白组分含有底物还原位点，这是一种结构未知的铁硫钼辅因子。簇和蛋白质的功能作用将通过晶体学研究来解决，至少2.5A分辨率的A. vinelandii mofe蛋白在存在和不存在结合配体（抑制剂和核苷酸）和不同氧化状态下：突变的mofe蛋白；以及与mofe蛋白相关的替代氮酶蛋白的结构。耐热红氧还蛋白和铁氧还蛋白。狂怒热球菌是一种生长在1000℃的超嗜热细菌。来自该生物的红氧还蛋白（精炼至至少0.96A分辨率）和铁氧还蛋白的晶体结构不仅将定义蛋白质- fe:S中心相互作用的细节，而且还将为表征这些蛋白质的热稳定性提供结构框架。