Site-Specific Mutation of Nitrogenase Proteins

固氮酶蛋白的位点特异性突变

• 批准号: 9120515
• 负责人: James Howard
• 金额: $ 32.1万
• 依托单位: University of Minnesota-Twin Cities
• 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: 1992-03-01 至 1995-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9120515&HistoricalAwards=false
• 关键词: Site; Specific; Mutation; Nitrogenase; Proteins

Dinitrogen reduction is essential for maintenance of the nitrogen cycle by replenishing ammonia lost through microbial denitrifiction Nitrogenase is a prototypic example of an enzyme with varied Fe:S chemistry associated with electron transfer and substrate reduction. In addition, it is an excellent model of energy transduction with ATP hydrolysis. The Fe-protein of nitrogenase is the obligate ATPase dependent electron transfer agent for substrate reduction. To study how Fe-protein functions in this role, the following questions will be investigated in the next grant period. 1. How is the 4Fe:4S cluster assembled in the FE- protein and how is the resultant cluster processed to the active state? 2. Where are the ATP/ADP binding sites in the Fe- protein? What are the different modes of nucleotide binding and how do they elicit the various structural-conformational changes in the protein?

氮素还原是通过补充微生物脱氮过程中损失的氨气来维持氮循环所必需的。固氮酶是一种具有不同铁的酶的典型例子：S化学与电子转移和底物还原有关。此外，它还是一种利用ATP水解法进行能量转导的极佳模型。固氮酶的铁蛋白是底物还原所必需的ATPase依赖的电子转移剂。为了研究铁蛋白如何在这一作用中发挥作用，将在下一次赠款期间调查以下问题。1.4Fe：4S簇是如何组装到Fe-蛋白中的，生成的簇是如何被加工成活性状态的？2.铁蛋白中的ATP/ADP结合部位在哪里？核苷酸结合的不同模式是什么？它们如何引起蛋白质的各种结构-构象变化？