Regulation of methionine metabolism in Bacillus subtilis

枯草芽孢杆菌蛋氨酸代谢的调控

• 批准号: 7094415
• 负责人: TINA M. HENKIN
• 金额: $ 28.59万
• 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 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7094415
• 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): The S box system is a novel global regulatory mechanism for control of genes involved in methionine metabolism in Gram-positive bacteria. Genes in the S box family contain a complex set of conserved primary sequence and structural elements upstream of the start of the coding sequence. These elements act in the nascent RNA to bind S-adenosylmethionine (SAM), and interaction with SAM results in a structural switch in the RNA that promotes premature termination of transcription. Lysine biosynthesis genes use a similar mechanism, with binding of lysine to nascent RNAs in the L box family to terminate transcription or prevent translation initiation. A new SAM-binding RNA element has now been identified in the upstream region of SAM synthetase genes of certain Gram-positive organisms, and this element, like the S box element, is predicted to regulate expression of the downstream coding sequence in response to SAM. These and related systems are widely used to regulate gene expression in Gram-positive bacteria, including important pathogens. The overall goals of this project are to investigate the molecular basis for specific recognition of effector molecules by the nascent RNA, and for calibration of the affinity of each class of RNA to physiologically relevant concentrations of the effector. A variety of genetic, biochemical, and structural biology approaches will be employed to elucidate both the RNA-effector interaction and the structural rearrangement necessary for the appropriate regulatory response to effector binding. The interaction between methionine gene regulation and the stringent response will also be explored. Work will focus on Bacillus subtilis as a model for analysis of these systems, and will also include analysis of the new SAM binding element from Enterococcus faecalis. This project will provide basic information about novel RNA-based mechanisms of gene regulation, and will also provide insight into metabolic regulation in pathogenic organisms that use these mechanisms. Gram-positive pathogens generally use regulatory mechanisms closely related to those found in Bacillus subtilis. Expression of determinants for pathogenicity are often regulated in response to physiological signals, and understanding how the cell monitors these signals is important for understanding bacterial virulence.

描述（由申请人提供）：S盒系统是一种新型的全球调节机制，用于控制革兰氏阳性细菌中蛋氨酸代谢的基因。 S盒家族中的基因包含一组复杂的保守主要序列和编码序列开始上游的结构元素。这些元素在新生的RNA中起作用以结合S-腺苷甲氨酸（SAM），与SAM的相互作用导致RNA中的结构开关促进转录的过早终止。赖氨酸生物合成基因使用类似的机制，赖氨酸与L盒家族中新生的RNA结合以终止转录或防止翻译起始。现在已经在某些革兰氏阳性生物的SAM合成酶基因的上游区域中鉴定出了一种新的SAM结合RNA元素，并且预计该元素像S盒元素一样，可以调节响应于SAM的下游编码顺序的表达。这些和相关的系统被广泛用于调节革兰氏阳性细菌（包括重要病原体）中的基因表达。该项目的总体目标是研究通过新生RNA特异性识别效应分子的分子基础，以及校准每类RNA对效应子的生理相关浓度的亲和力。将采用多种遗传，生化和结构生物学方法来阐明RNA效应器相互作用以及适当的调节响应对效应子结合所必需的结构重排。还将探索蛋氨酸基因调节与严格反应之间的相互作用。工作将集中于枯草芽孢杆菌作为分析这些系统的模型，还将包括对粪肠球菌的新SAM结合元件的分析。该项目将提供有关基于基因调节的新型机制的基本信息，还将提供对使用这些机制的致病生物代谢调节的见解。革兰氏阳性病原体通常使用与枯草芽孢杆菌中发现的调节机制。通常根据生理信号来调节病原性决定因素的表达，并了解细胞监测这些信号对于理解细菌毒力的重要性。