Nitrogenase Assembly Mechanism

描述（由申请人提供）：氮酶是一种复杂的金属酶，催化生物系统中最显著的化学转化之一：核苷酸依赖的大气二氮还原为生物可利用的氨。破译氮酶的组装机制是一个突出的兴趣，不仅因为它与氮酶特异性反应有重要的相关性，而且因为它对一般金属蛋白的生物发生具有巨大的意义。在此，我们建议通过结合遗传学、生物化学、光谱和结构方法来极大地扩展我们对氮酶组装过程的理解。拟研究的重点是固氮菌vinelandii钼氮化酶的MoFe蛋白。通过我们所提出的研究，我们期望进一步完善MoFe蛋白及其相关簇的生物合成途径，最终目的是揭开氮酶组装的分子机制。此外，利用氮酶作为模型系统，我们也希望提供生物金属团簇组装的一般主题，从长远来看，这可能有助于开发复杂金属团簇化学合成的成功策略。公共卫生相关性：氮酶催化大气中的二氮转化为生物可利用的氨，从而为人类的生存提供还原后的氮，这是核酸和蛋白质的重要组成部分。这一特别的提议涉及到氮酶MoFe蛋白及其相关金属团簇的组装，这些研究的结果有望为生物金属团簇组装提供一般主题，并促进未来化学合成具有催化活性的金属团簇的成本效益策略的发展。因此，我们提出的研究除了与人类健康的内在相关性外，还可能具有额外的经济价值。

DESCRIPTION (provided by applicant): Nitrogenase is a complex metalloenzyme that catalyzes one of the most remarkable chemical transformations in biological systems: the nucleotide-dependent reduction of atmospheric dinitrogen to bioavailable ammonia. There is an outstanding interest in decoding the assembly mechanism of nitrogenase, not only because of its significant relevance to nitrogenase-specific reactions, but also because of its tremendous implication for general metalloprotein biogenesis. Here we propose to greatly expand our understanding of the nitrogenase assembly process by combined genetic, biochemical, spectroscopic and structural approaches. The MoFe protein of the molybdenum nitrogenase of Azotobacter vinelandii will be the focus of the proposed investigation. Through our proposed studies, we expect to further refine the biosynthetic pathways of MoFe protein and its associated clusters, a continuous effort with an ultimate goal to unravel the molecular mechanism of nitrogenase assembly. Furthermore, using nitrogenase as a model system, we also hope to provide general themes of biological metal cluster assembly, which may, in the long run, prove instrumental in developing successful strategies for the chemical synthesis of complex metalloclusters. . PUBLIC HEALTH RELEVANCE: Nitrogenase catalyzes the transformation of atmospheric dinitrogen to bioavailable ammonia, thereby supplying the reduced nitrogen, an essential component of nucleic acids and proteins, for the existence of human population. This particular proposal deals with the assembly of nitrogenase MoFe protein and its associated metalloclusters and the outcome of these studies will hopefully provide general themes of biological metal cluster assembly and facilitate future development of cost-efficient strategies for the chemical synthesis of catalytically active metalloclusters. As such, our proposed research may have additional economic value in addition to its intrinsic relevancy to human health.