COENZYME F420 BIOSYNTHESIS IN MYCOBACTERIUM

描述：我们在分枝杆菌中发现一种新的酶 (辅酶-F420依赖的葡萄糖-6-P脱氢酶)，以及我们最新的 证明缺乏这种酶的耻垢分枝杆菌突变体生长不良， 对氧化应激的敏感性增加表明F420是 对分枝杆菌健康很重要。F420与分枝杆菌的关系 新陈代谢是意想不到的，因为它是一种电子转移辅酶，很少 在细菌中发现，但通常在古生菌中发现。分枝杆菌致病 几种严重的疾病，包括肺结核、麻风病和艾滋病 机会性感染。如果F420对毒力很重要，我们认为 了解F420的代谢和生物合成将为如何 开发抗分枝杆菌病的新药。我们 建议确定辅酶F420生物合成的遗传基础 分枝杆菌，为了确定这种辅酶对生长的重要性， 氧化应激反应和毒性。这将通过以下方式实现 耻垢分枝杆菌不能产生F420的突变体的分离、克隆和测序 受影响的基因，利用这些信息产生F420- 结核分枝杆菌突变体，评估ALL的体外特性 突变，并尽可能多地推断每个基因的作用。 结核分枝杆菌突变株的毒力将在巨噬细胞和 动物模型。主要假设是：F420对于 分枝杆菌作为氧化还原辅酶在生长、保护氧化应激中的作用 反应或代谢的其他方面；F420对M。 结核病的毒力；F420生物合成基因将在很大程度上 与产甲烷古生菌中提出的生物合成途径一致。

DESCRIPTION: Our discovery of a novel enzyme in mycobacteria (coenzyme-F420-dependent glucose-6-P dehydrogenase), and our recent demonstration that M. smegmatis mutants lacking this enzyme grow poorly and have increased sensitivity to oxidative stress suggest that F420 is important for Mycobacterium fitness. F420 involvement in Mycobacterium metabolism was unexpected, since it is an electron-transfer coenzyme seldom found in Bacteria, but commonly found in Archaea. Mycobacteria cause several serious diseases, including tuberculosis, leprosy, and AIDS opportunistic infections. If F420 is important for virulence, we think that understanding F420 metabolism and biosynthesis will provide clues on how to develop new classes of drugs active against mycobacterial disease. We propose to determine the genetic basis for coenzyme F420 biosynthesis in Mycobacterium, and to define the importance of this coenzyme for growth, oxidative stress response, and virulence. This will be achieved by isolating M. smegmatis mutants that cannot make F420, cloning and sequencing the genes affected, using this information to create F420-minus Mycobacterium tuberculosis mutants, evaluating the vitro properties of all mutants, and deducing as much as possible concerning the role of each gene. The virulence of M. tuberculosis mutants will be examined in macrophage and animal models. The main hypotheses are that: F420 is important to mycobacteria as a redox coenzyme in growth, protective oxidative stress response, or other aspects of metabolism; F420 is important for M. tuberculosis virulence; the F420 biosynthesis genes will be largely consistent with the proposed biosynthesis pathway in methanogenic Archaea.