REGULATION OF GLUTAMATE SYNTHESIS IN BACILLUS SUBTILIS

这个项目的长期目标是在分子水平上理解 控制酶的合成和活性的机制 在枯草芽孢杆菌中将乙酰辅酶A转化为谷氨酸。这条路，它是 是产生能量、降低功率和生物合成的关键 积木，也是碳和氮的结合点 新陈代谢，在细菌分化中起着关键的调节作用。 编码这一途径的酶的基因，柠檬酸合成酶， 乌头酸酶、异柠檬酸脱氢酶和谷氨酸合成酶都是 克隆的，并已被证明在转录水平上受到调控。 这个项目的具体目标是鉴定和分离蛋白质。 调节这些基因中的每一个，以推断细胞内的代谢物 控制每个调节蛋白活性并重建每个 体外调控系统。其中一种蛋白质已经被 鉴定出：谷氨酸合成酶合成的正调控因子GLTC， 是LysR家族的一员。由于人们对此知之甚少 这一蛋白质家族如何接触DNA并刺激转录， GLTC的区域有助于DNA结合，效应器结合， 多聚体和与RNA聚合酶的相互作用将成为目标 诱变和遗传选择。枯草杆菌系统是主要的 革兰氏阳性菌和原核生物的研究范式 差异化。枯草杆菌基因表达的基础研究， 新陈代谢的调节和对环境的反应是高度的 提供关于相关致病细菌生物学的信息，并提供 一种研究具有普遍生物学重要性的问题的方法 在生理上和基因上容易操纵的有机体。

The long-term goal of this project is to understand at the molecular level the mechanisms that control synthesis and activity of the enzymes that convert acetyl CoA to glutamate in Bacillus subtilis. This pathway, which is critical for generation of energy, reducing power, and biosynthetic building blocks, is also the junction between carbon and nitrogen metabolism and plays a key regulatory role in bacterial differentiation. Genes that encode the enzymes of this pathway, citrate synthase, aconitase, isocitrate dehydrogenase, and glutamate synthase, have all been cloned and have been shown to be regulated at the level of transcription. The specific aims of this project are to identify and isolate the proteins that regulate each of these genes, to deduce the intracellular metabolites that control activity of each regulatory protein and to reconstruct each regulatory system in vitro. One of these proteins has already been identified; GltC, the positive regulator of glutamate synthase synthesis, is a member of the LysR family. Since relatively little is known about how this family of proteins contacts DNA and stimulates transcription, the regions of GltC that contribute to DNA binding, effector binding, multimerization, and interaction with RNA polymerase will be targets for mutagenesis and genetic selection. The B. subtilis system is the primary paradigm for studies of Gram-positive bacteria and prokaryotic differentiation. Fundamental studies of B. subtilis gene expression, regulation of metabolism, and response to the environment are highly informative about the biology of related pathogenic bacteria and provide a means of studying issues of universal biological importance in an organism that is easily manipulated physiologically and genetically.