REGULATION OF MICROBIAL NITROGEN METABOLISM

产气克雷伯氏菌中组氨酸利用（hut）的基因是 是大量基因的典型特征，其表达受到严格调控 通过可用的氮气供应。 因此， 作为这种多效性控制的模型系统。 的目标 本研究拟开发一种体外转录系统， 对于K.产气菌，其响应于 氮调节因子，并研究其分子基础 调控 五年提案期的具体目标是： (1)调节区（hutP）的物理表征，包括 该区域的DNA序列和鉴定与该区域结合的位点 调节蛋白结合;（2）hutP区域的遗传分析， 包括分离和绘制不能对HUT产生反应的突变体， 氮调节;（3）表征所需的遗传因素， 氮调节hutP表达;（4）转录调节 从hutP在体外，包括CAP+cAMP的调节和纯化， 氮激活蛋白

The genes for histidine utilization (hut) in Klebsiella aerogenes are typical of a large number of genes whose expression is strictly regulated by the available supply of nitrogen. Thus nitrogen regulation of hut serves as a model system for this kind of pleiotropic control. The goal of the research proposed here is to develop an in vitro transcription system for the hut operon of K. aerogenes that is responsive to regulation by the nitrogen regulatory factor(s) and to study the molecular basis for that regulation. The specific objectives of the five year proposal period are: (1) Physical characterization of the regulatory region (hutP) including the DNA sequence of the region and identification of the sites to which regulatory proteins bind; (2) Genetic analysis of the hutP region, including isolation and mapping of hut mutants unable to respond to nitrogen regulation; (3) Characterization of genetic factors required for nitrogen regulation of hutP expression; and (4) Regulation of transcription from hutP in vitro, including regulation by CAP+cAMP and purification of the nitrogen activating protein.