RNA POLYMERASE AND BACTERIAL DIFFERENTIATION

RNA 聚合酶和细菌分化

• 批准号: 2061172
• 负责人: Charles P. Moran
• 金额: $ 25.5万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-07-01 至 1996-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2061172
• 关键词: Bacillus subtilis; DNA directed RNA polymerase; DNA footprinting; bacterial genetics; cell differentiation; genetic promoter element; genetic transcription; immunoelectron microscopy; methylation; natural gene amplification; operon; phosphorylation; site directed mutagenesis; spores; transcription factor

As the bacterium Bacillus subtilis differentiates from the vegetative form into a dormant endospore, complex morphological and physiological changes that occur that require the expression of many genes. During the process, new RNA polymerase sigma subunits appear, displacing one another and conferring on the RNA polymerase different specificities for the recognition of different classes of promoters. This mechanism of altering transcriptional specificity is a fundamental element in the regulation of sporulation gene expression. However, non-sigma regulatory factors are also essential for the regulation of gene expression during sporulation. Experiments are proposed to determine the role of different secondary sigma factors in sporulation and how the primary sigma factor in vegetative cells, theta A, is used to direct transcription of at least two key operons during sporulation. Additional experiments are proposed to determine how expression of specific genes is limited exclusively to one of the two compartments of the differentiating cell. The problem of regulating ordered expression of many different sets of genes is a common one in biology, faced in every procaryotic and eukaryotic organism that must execute a complex program of development. Many specific aspects of the solution to this problem will be directly relevant to understanding the regulation of differentiation and secondary metabolism in a broad range of bacteria. Examples include antibiotic biosynthesis in Streptomyces and the production virulence factors bacterial pathogens. Furthermore, the sporulation-induced transcription factors present an opportunity to study the interactions of sigma factors and RNA polymerase with several types of ancillary transcription factors. The biochemical principals that govern regulation of promoter activity by combinations of these factors are probably relevant to RNA polymerases in all organisms.

随着细菌枯草细菌与营养区分开 形成休眠的内孢子，复杂的形态和生理 需要许多基因表达的变化。 期间 该过程，出现了新的RNA聚合酶Sigma亚基，替代一个 另一个并赋予RNA聚合酶不同的特异性 对不同类别的启动子的认可。 这种机制 改变转录特异性是 调节孢子型基因表达。 但是，非sigma 调节因素对于调节基因也是必不可少的 孢子形成期间的表达。 提出了实验以确定不同次级的作用 孢子体中的西格玛因子以及主要的Sigma因子如何因素 theta a的营养细胞用于直接转录至少 孢子形成期间有两个关键操纵子。 提出了其他实验 确定特定基因的表达如何仅限于 区分细胞的两个隔室之一。 调节许多不同集的有序表达的问题 基因是生物学中常见的基因，面临着每个procaryotic和 必须执行复杂发展程序的真核生物。 解决该问题的解决方案的许多具体方面将直接 与理解分化的调节和 在广泛的细菌中的二级代谢。 示例包括 链霉菌和生产毒力的抗生素生物合成 因素细菌病原体。 此外，孢子引起的 转录因子提供了研究相互作用的机会 具有几种辅助的Sigma因子和RNA聚合酶 转录因子。 管理的生化原则 通过这些因素的组合来调节启动子活性是 可能与所有生物中的RNA聚合酶有关。