REGULATION OF METHIONINE METABOLISM IN BACILLUS SUBTILIS

枯草芽孢杆菌蛋氨酸代谢的调控

• 批准号: 6526074
• 负责人: TINA M. HENKIN
• 金额: $ 25.81万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6526074
• 关键词: Bacillus subtilis; RNA binding protein; aminoacid metabolism; bacterial genetics; bacterial proteins; biochemistry; cell free system; genetic regulation; genetic terminator element; guanine nucleotides; intermolecular interaction; methionine; molecular genetics; nucleic acid sequence; nucleic acid structure; protein reconstitution; protein structure function; reporter genes; site directed mutagenesis; suppressor mutations; transcription factor; transcription termination

DESCRIPTION (provided by applicant): A novel global regulation system for control of genes involved in methionine metabolism has been uncovered in Bacillus subtilis. Genes utilizing this mechanism, designated the S box family, contain in their mRNA leader regions a complex set of conserved primary sequence and structural elements, including a transcriptional terminator, competing antiterminator, and anti-antiterminator. Genetic analyses indicate that during growth in methionine, sequences in the leader are required for stabilization of the anti-antiterminator, which prevents formation of the antiterminator, which in turn allows termination. The molecular mechanism for control of the leader RNA structure in response to methionine levels is unknown, although preliminary studies suggest that binding of a regulatory factor is required to prevent readthrough. This system is widely used for control of methionine-related genes in a variety of Gram-positive bacteria, including important pathogens such as Staphylococcus aureus, and is also found in the Gram-negative bacteria Chlorobium tepidum and Geobacter sulforreducens. Eleven transcriptional units are controlled by this mechanism in B. subtilis alone, so the total number of genes involved is high. The major goal of this study is to further investigate the molecular mechanism of transcription termination control, and to elucidate the physiological role of this system, using a combination of genetic and biochemical approaches. The required cis-acting sequence elements will be identified by site-directed mutagenesis. The trans-acting regulatory factors required for the methionine response will be identified, and the system will be examined both in vivo and in vitro. A requirement for ppGpp for efficient readthrough in vivo has been demonstrated, and the molecular basis for this requirement will be examined. Finally, the physiological role of genes of unknown function which appear to be regulated by this mechanism will be examined.

描述（由申请人提供）：一种新型的全球监管系统 在蛋氨酸代谢中涉及的基因的控制已在 枯草芽孢杆菌。利用这种机制的基因指定了S盒子家族， 在其mRNA领导区域中包含一组复杂的保守主要原则 序列和结构元素，包括转录终结子， 竞争性抗固定器和抗驱动器。遗传分析表明 在蛋氨酸的生长过程中，领导者需要序列 稳定抗侵蚀剂，以防止形成 抗官剂，这又允许终止。分子机制 响应蛋氨酸水平的铅RNA结构的控制是 未知，尽管初步研究表明调节性的结合 需要因素来防止阅读。该系统被广泛用于 在多种革兰氏阳性细菌中控制蛋氨酸相关基因， 包括重要的病原体，例如金黄色葡萄球菌，也发现 在革兰氏阴性细菌中，绿木叶绿素和地球杆菌磺胺药物。 11个转录单元在枯草芽孢杆菌中受此机制控制 单独，因此所涉及的基因总数很高。 这项研究的主要目的是进一步研究分子机制 转录终止控制，并阐明生理作用 该系统，结合了遗传和生化方法。这 所需的顺式作用序列元素将通过站点定向确定 诱变。蛋氨酸所需的跨作用调节因素 将确定响应，并将在体内检查系统和 体外。 PPGPP在体内有效读取的要求是 证明，将检查该需求的分子基础。 最后，未知功能基因的生理作用似乎是 受此机制的调节将进行检查。