Nitrogenase assembly mechanism

固氮酶组装机制

• 批准号: 10524039
• 负责人: Markus W Ribbe
• 金额: $ 34.07万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10524039
• 关键词: Binding; Biochemical; Biomimetics; Carbon; Chemicals; Complex; Coupling; Cryoelectron Microscopy; Crystallography; Enzymes; Genetic; Health; Human; Knowledge; Molybdenum; Nitrogen; Nitrogenase; Pathway interactions; Population; Reaction; Research; Selenite; Source; Sulfites; Sulfur; Variant; analog; biological systems; carbene; catalyst; chemical synthesis; deprotonation; homocitrate; in vivo; insight; interstitial; methyl group; tellurite; usability

PROJECT SUMMARY Nitrogenase reaction represents a major source of the usable form of nitrogen that supports the existence of human population. As such, understanding how small building blocks are assembled into a functional nitrogenase entity is of significant relevance to human health. Using combined genetic, biochemical, spectroscopic and structural approaches, we propose to investigate how M-cluster, the unique metallocofactor of molybdenum nitrogenase, is assembled into a functional unit. Specifically, we will investigate how an interstitial carbide is inserted via a radical SAM-dependent mechanism concomitant with fusion of two 4Fe modules into an 8Fe core of the M-cluster, what is the in vivo donor/carrier of the “9th sulfur” and how this sulfur is inserted into the catalytically important belt region of the 8Fe core, and how Mo is mobilized and inserted into the 8Fe core to form a mature M-cluster. Through our proposed studies, we expect to further refine the biosynthetic pathway of the unique metallocofactor of nitrogenase, which will provide crucial insights into the structural-functional relationship of this important enzyme and reveal some general principles of the assembly mechanisms of complex metalloclusters in biological systems.

项目摘要 固氮酶反应代表了支持植物生长的氮的可用形式的主要来源。 人口的存在。因此，了解构建块有多小 组装成功能性固氮酶实体与人类健康显著相关。使用 结合遗传、生物化学、光谱和结构方法，我们建议 研究钼固氮酶独特的金属辅因子M-簇是如何 组装成功能单元。具体来说，我们将研究间隙碳化物是如何 通过自由基SAM依赖机制插入，伴随着两个4Fe模块的融合 进入M-簇的8 Fe核心，什么是“第九硫”的体内供体/载体，以及这是如何形成的。 硫被插入到8 Fe芯的催化重要带区域中，并且Mo是如何被插入到8 Fe芯的催化重要带区域中的。 移动并插入到8 Fe核心中以形成成熟的M-簇。通过我们提出的 研究，我们希望进一步完善独特的金属辅因子的生物合成途径， 固氮酶，这将提供重要的见解的结构功能关系，这 并揭示了复合物组装机理的一些一般性原理 生物系统中的集群。