BIOCHEMISTRY OF A NOVEL IRON-SULFUR FLAVOPROTEIN

在产甲烷的嗜热甲烷单胞菌中首次发现了一种新的铁-硫黄素蛋白。自从这一发现以来，越来越多的证据有力地表明，这种电子载体广泛分布于代谢多样化的原核生物中，这些原核生物跨越细菌和古生物领域。我计划对这种新的黄素蛋白进行生化表征，以了解蛋白质环境是如何控制FMN的氧化还原电位的。我将使用位点定向替换残基，并使用生化和生物物理方法表征变体，以确定选定的残基如何影响FMN的性质。我还计划通过确定天然的电子受体来进一步研究ISF的生理作用。这些结果有望使人们更好地理解这种电子载体在所有原核生物中的作用，以及黄素蛋白的一般生物化学。

A novel iron-sulfur flavoprotein was first discovered in the methane-producing archaeon Methanosarcina thermophila. Since this discovery, evidence has accumulated strongly indicating that this electron carrier is widely distributed in metabolically diverse procaryotes that span both the Bacteria and Archaea domains. I plan to biochemically characterize this novel flavoprotein to learn how the protein environment controls the redox potential of the FMN. I will use site-directed replacement of residues and characterize the variants using both biochemical and biophysical methods to determine how the selected residues influence properties of the FMN. I also plan to further examine the physiological role of Isf by determining the natural electron acceptor. The results are expected to lead to a better understanding of the role for this electron carrier in all procaryotes and the biochemistry of flavoproteins in general.