ALTERNATIVE SIGMA FACTORS AND ANTIBIOTIC SYNTHESIS

替代 Sigma 因子和抗生素合成

• 批准号: 2668498
• 负责人: GEORGE H JONES
• 金额: $ 18.79万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-03-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2668498
• 关键词: DNA directed RNA polymerase; SDS polyacrylamide gel electrophoresis; Streptomyces; actinomycin; bacterial genetics; gene expression; genetic regulation; guanine nucleotides; molecular cloning; mutant; nucleic acid sequence; protein biosynthesis; transcription factor

Alternative sigma factors play an important role in the regulation of bacterial gene expression. The proposed research will explore the role of an alternative sigma factor, sigmaE, in the regulation of actinomycin biosynthesis in the Gram-positive bacterium, Streptomyces antibioticus. Specific experiments to be performed will include: (1)identification of an RNA polymerase holoenzyme in Streptomyces antibioticus capable of transcribing the phenoxazinone synthase gene (phsA) and verification of sigmaE as the sigma factor associated with that holoenzyme; (2)characterization of the cloned gene for sigmaE from S. antibioticus; (3)examination of the role of sigmaE in the regulation of the expression of phsA and other genes involved in the biosynthesis of actinomycin - Disruption of the sigE gene; (4)expression of the cloned sigE gene in S. antibioticus sigE null mutants; (5)examination of the regulation of sigE expression in S. antibioticus; (6)examination of the role of guanosine tetraphosphate in regulating the expression of the sigE gene; and (7)identification of other genes in S. antibioticus whose transcription is dependent on sigE. The proposed studies will mesh well with the longer term research objectives of the applicant laboratory. In particular, the proposed research will connect directly to ongoing experiments related to the role of highly phosphorylated guanine nucleotides in the regulation of actinomycin biosynthesis and to experiments dealing with the regulation of phenoxazinone synthase expression by glucose. The suggested experiments will add significantly to our understanding of mechanisms involved in the regulation of prokaryotic gene expression generally and to our specific comprehension of mechanisms regulating antibiotic production. As over 70 % of the antibioticus used in clinical and veterinary medicine are produced by members of the genus Streptomyces, a thorough understanding of genetic regulatory mechanisms involved in antibiotic production is essential if these organisms are to be manipulated to produce new and more effective chemotherapeutic agents.

替代西格玛因素在调节中起重要作用 细菌基因表达。拟议的研究将探讨 放线霉素调节的替代西格玛因子Sigmae 革兰氏阳性细菌，链霉菌抗生素中的生物合成。 要执行的具体实验将包括：（1）识别 RNA聚合酶全酶在链霉菌抗生素中的能力 转录苯氧唑合酶基因（PHSA）和验证 Sigmae作为与全酶有关的Sigma因子； （2）抗生素链球菌的克隆基因的特征； （3）检查Sigmae在表达调节中的作用 pHSA和其他参与放线菌素生物合成的基因 - sige基因的破坏； （4）克隆的Sige基因在S中的表达。 抗生素sige null突变体； （5）检查SIGE的调节 抗生素链球菌的表达； （6）检查鸟嘌呤的作用 四磷酸在调节SIGE基因的表达方面；和 （7）鉴定转录的抗生素中其他基因的鉴定 取决于sige。拟议的研究将与更长 申请人实验室的术语研究目标。特别是 拟议的研究将直接连接到与之相关的正在进行的实验 高度磷酸化的鸟嘌呤核苷酸在调节中的作用 放线霉素的生物合成和针对调节的实验 葡萄糖的苯氧唑合酶表达。 建议的实验 将大大增加我们对涉及机制的理解 总体和我们的特异性调节原核基因表达 理解调节抗生素产生的机制。超过70 用于临床和兽医医学中使用的抗生素的％是 由链霉菌属的成员生产，对 抗生素产生涉及的遗传调节机制是 如果要操纵这些生物以产生新的以及更多 有效的化学治疗剂。