SGER: Novel Nitrogenase-like Proteins and the Evolution of the Nitrogen Cycle

SGER：新型固氮酶样蛋白和氮循环的演变

• 批准号: 0415283
• 负责人: Robert Blankenship
• 金额: $ 9.57万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-15 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0415283&HistoricalAwards=false
• 关键词: SGER; Novel; Nitrogenase; like; Proteins

This SGER project is concerned with the characterization of a putative new class of enzymes evolutionarily related to nitrogenase. These proteins have been discovered using genomic methods in a number of organisms, including several that are not diazotrophic. The proteins are evolutionarily related to nitrogenase but almost certainly catalyze other, as yet unknown, chemical reactions. These proteins may be the direct descendents of the primitive ancestors of nitrogenase, because of their basal position in the phylogenetic tree and the single type of subunit in the reductase portion of the complex. In this project, genes for these nitrogenase-like proteins (NflH and NflD) will be cloned from Methanococcus jannaschii and will be expressed in E. coli. Using antibodies obtained from these recombinant proteins, native forms of these same proteins from M. jannaschii will be purified and characterized. It is possible that a unique activity will be determined for these proteins, which could imply a role for a pre-nitrogenase homolog on the early Earth. A further understanding of the mechanism of nitrogenase might also be realized, if a similar substrate or activity is found in these homologs.Broader Impacts: This project will enhance our understanding of the origin and evolution of the nitrogen cycle, which will give important insights into the early evolution of life and the origin of metabolism. This project will involve training of a postdoctoral fellow and will contribute to the development of a scientifically trained workforce.

这个SGER项目关注的是一个假定的新的一类酶进化相关的固氮酶的特性。这些蛋白质已经在许多生物体中使用基因组方法发现，包括几种非固氮生物。这些蛋白质在进化上与固氮酶有关，但几乎肯定催化其他未知的化学反应。这些蛋白质可能是固氮酶原始祖先的直接后代，因为它们在系统发育树中的基础位置和复合物还原酶部分的单一类型的亚基。在本项目中，将从詹氏甲烷球菌中克隆这些固氮酶样蛋白（NflH和NflD）的基因，并在大肠杆菌中表达。杆菌使用从这些重组蛋白获得的抗体，从M.将对詹氏菌进行纯化和鉴定。这些蛋白质可能具有独特的活性，这可能意味着早期地球上前固氮酶同系物的作用。更广泛的影响：本项目将增强我们对氮循环起源和进化的理解，这将对生命的早期进化和新陈代谢的起源提供重要的见解。该项目将包括培训一名博士后研究员，并将有助于发展一支受过科学培训的工作队伍。