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)为了确定在启动子处的碳调节机制， （2）为了开始分析氮调节， 启动子的hutUH操纵子，和（3）为了扩大我们的理解， hut操纵子本身。

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) To determine the mechanism of carbon regulation at the promoter of the hutUH operon, (2) To begin an analysis of the nitrogen regulation at the promoter of the hutUH operon, and (3) To extend our understanding of the hut operons themselves.