Regulation of Nitrogen Metabolism in Bacillus subtilis

枯草芽孢杆菌氮代谢的调控

• 批准号: 6611845
• 负责人: SUSAN H. FISHER
• 金额: $ 34.72万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6611845
• 关键词: Bacillus subtilis; DNA binding protein; SDS polyacrylamide gel electrophoresis; Staphylococcus; Streptococcus; bacterial genetics; bacterial proteins; binding sites; biological signal transduction; gene expression; genetic regulation; glutamate ammonia ligase; microorganism growth; microorganism metabolism; molecular cloning; nitrogen metabolism; nucleic acid sequence; polymerase chain reaction; protein protein interaction; site directed mutagenesis; transcription factor

DESCRIPTION (provided by applicant): A fundamental question in cellular physiology is how cells recognize and respond to changes in their environment. The applicant's overall goal is to understand the network of regulatory systems controlling the utilization of nitrogen compounds in the model low G+C Gram-positive bacterium, Bacillus subtilis. These studies will provide insight into how nitrogen metabolism is controlled in the agriculturally and commercially important Bacillus spp. as well as in important low G+C Gram-positive pathogens such as Staphylococcus, Streptococcus and Enterococcus. Two very similar global transcription factors, GInR and TnrA, are responsible for the activation of gene expression during nitrogen-limited growth in B. subtilis. The activity of TnrA is regulated by a novel signal transduction system where the feedback-inhibited form of GS binds TnrA, blocking its DNA binding activity. One goal of this project is to understand the molecular mechanism responsible for the protein-protein interaction between TnrA and GS. Generalized and site-directed mutagenesis will be performed to identify amino acid residues required for feedback inhibition of GS and for the interaction between TnrA and GS. The stoichiometry and equilibrium binding constant of the interaction between GS and TnrA will be determined. The TnrA binding site will be defined by protein footprinting. All the available genetic evidence indicates that the feedback-inhibited form of GS also regulates the activity of GInR. It will be determined whether GS directly binds to GInR, activating its DNA binding activity. Alternatively feedback inhibited GS may indirectly regulate GlnR by a partner switching mechanism. Biochemical and genetic approaches will be used to search for factors required for the regulation of GInR activity by glutamine synthetase.

描述（由申请人提供）：细胞生理学的一个基本问题是细胞如何识别和响应环境的变化。申请人的总体目标是了解控制模型低G+C革兰氏阳性细菌（枯草芽孢杆菌）氮化合物利用的调节系统网络。这些研究将深入了解在农业和商业上重要的芽孢杆菌以及重要的低G+C革兰氏阳性病原体（如葡萄球菌、链球菌和肠球菌）中氮代谢是如何控制的。