REGULATION OF MICROBIAL NITROGEN METABOLISM

微生物氮代谢的调节

• 批准号: 2184565
• 负责人: ROBERT A BENDER
• 金额: $ 26.51万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-05-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2184565
• 关键词: REGULATION; MICROBIAL; NITROGEN; METABOLISM

The overall goal of this research is to understand how gene expression is activated in response to global regulatory signals like nitrogen starvation. In particular, this research focuses on how to different positive activators, NAC and CAP-cAMP (responding to nitrogen and carbon starvation respectively) can each activate transcription from the same promoter, the hutU promoter of the histidine utilization operons. The effects of NAC on the kinetic parameters (rate and yield constants) for transcription initiation by RNA Polymerase. These effects will be compared with those at al chimeric hut-lac promoter where NAC activates transcription from the lacZ promoter. Similarly, the effects of CAP-cAMP on the hutU promoter will be determined both to compare with NAC and to explain the effects of two different CAP-binding sites within the hutU promoter. A parallel set of experiments will examine the interactions between NAC and RNA Polymerase, concentrating especially on the C- terminus domain of the a subunit. In addition, the ability of NAC to repress transcription of some genes (e.g. the ghdA gene) will be examined to explain why repression by NAC appears to be more complex than activation. The structure of the NAC protein itself will be probed by a combination of physical methods (e.g. crystallography and identification of the smallest active domain of NAC) and genetic approaches (to identify domains that interact with DNA, RNA Polymerase, etc). Finally this project will result in the continued improvement of the tools for genetic analysis of Klebisella aerogenes, including a study of a novel mode of lysogeny for phage lambda, and an analysis of a new form of NTR-independent nitrogen regulation.

这项研究的总体目标是了解基因表达如何 响应氮等全球监管信号而被激活 饥饿。 特别是，本研究重点关注如何不同 正激活剂、NAC 和 CAP-cAMP（响应氮和碳 分别饥饿）可以各自激活来自相同的转录 启动子，组氨酸利用操纵子的hutU启动子。 NAC对动力学参数（速率和产率常数）的影响 用于 RNA 聚合酶的转录起始。 这些影响将是 与 NAC 激活的 al 嵌合 hut-lac 启动子相比 从 lacZ 启动子转录。 同样，CAP-cAMP 的作用 将确定 hutU 启动子上的信息以与 NAC 进行比较并 解释 hutU 内两个不同 CAP 结合位点的影响 发起人。 一组平行实验将检查相互作用 NAC 和 RNA 聚合酶之间，特别集中在 C- a 亚基的末端结构域。 此外，NAC 还具有抑制某些基因转录的能力 （例如 ghdA 基因）将被检查以解释为什么 NAC 抑制 似乎比激活更复杂。 NAC的结构 蛋白质本身将通过物理方法的组合来探测（例如， NAC 最小活性结构域的晶体学和鉴定） 和遗传方法（识别与 DNA、RNA 相互作用的域） 聚合酶等）。 最后，该项目将导致持续改进 用于产气克雷比氏菌遗传分析的工具，包括以下研究 噬菌体 lambda 的新型溶源模式以及新形式的分析 不依赖NTR的氮调节。