Genetic Analysis of Global Streptomyces Antibiotic Regulation

全球链霉菌抗生素调控的遗传分析

• 批准号: 9604055
• 负责人: Wendy Champness
• 金额: $ 32.5万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-15 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9604055&HistoricalAwards=false
• 关键词: Genetic; Analysis; Global; Streptomyces; Antibiotic

Champness 9604055 Streptomycetes, filamentous soil bacteria, possess two characteristics that make them attractive prokaryotes for study: they develop into complex, multicellular, differentiated colonies and they produce a vast array of secondary metabolites, many of which are useful as antibiotics. Antibiotic production is usually coupled to morphological differentiation, beginning at the transition between vegetative growth and production of pre-spore differentiated hyphae. The long term goal of this research is to discover the genes that regulate antibiotic synthesis, to understand how they function, and to determine their functional relationships in the regulatory network controlling antibiotic gene expression. The immediate objectives of this proposal focus on three genetic elements discovered in previous NSF funding periods: absA, absB and mia. Research will proceed along the following lines: 1. The mechanism by which the absA-encoded signal transduction system exerts global negative control over antibiotic gene expression will be determined. Genetic, molecular genetic and biochemical experiments will: a) characterize functionally important regions and interactions of the AbsA1/A2 "sensor-kinase" and response regulator proteins; b) establish the role of protein phosphorylation in AbsA-mediated regulation; and c) explore the genetic pathway through which absA regulates expression of the antibiotic "pathway-specific regulators." 2. The absB gene and its probable gene product, an RNaseIII, will be characterized through determination of the RNaseIII (absB) null phenotype, functional studies on the S. coelicolor RNaseIII, and identification of candidate RNaseIII targets. 3. The 190 nt mia sequence, which exerts multi-copy inhibition of antibiotic gene expression, will be characterized to determine the functional regions of the sequence. The results of the proposed work promise to elucidate aspec ts of the regulatory programs controlling streptomycete gene expression, and to expand our understanding of microbial multicellular differentiation.

链霉菌，丝状土壤细菌，具有两个特点，使他们有吸引力的原核生物的研究：他们发展成复杂的，多细胞的，分化的菌落，他们产生了大量的次级代谢产物，其中许多是有用的抗生素。 抗生素的产生通常与形态分化相结合，开始于营养生长和孢子前分化菌丝的产生之间的过渡。 本研究的长期目标是发现调控抗生素合成的基因，了解它们的功能，并确定它们在控制抗生素基因表达的调控网络中的功能关系。 该提案的近期目标集中在之前NSF资助期间发现的三个遗传元素：absA，absB和mia。 研究将沿着以下路线进行：1. absA编码的信号转导系统发挥全局作用的机制 确定抗生素基因表达的阴性对照。 遗传的， 分子遗传学和生物化学实验将：a）功能表征 AbsA 1/A2“传感器-激酶”和应答的重要区域和相互作用 调节蛋白; B）确定蛋白磷酸化在AbsA介导的细胞凋亡中的作用。 调控;以及c）探索absA调控的遗传途径 抗生素途径特异性调节剂的表达。“2. absB基因及其可能的基因产物RNaseIII将被表征 通过测定RNaseIII（absB）无效表型，对 色葡萄coelicolorRNaseIII，并鉴定候选RNaseIII靶标。 3. 190 nt mia序列，发挥抗生素基因的多拷贝抑制作用 将表征表达，以确定序列的功能区。 这些结果有望阐明链霉菌基因表达调控程序的各个方面，并扩展我们对微生物多细胞分化的理解。