MOLECULAR GENETICS OF BACILLUS SUBTILIS CYTOCHROME AA3

枯草芽孢杆菌细胞色素 AA3 的分子遗传学

• 批准号: 3303712
• 负责人: HARRY W TABER
• 金额: $ 11.64万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-06 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3303712
• 关键词: Bacillus subtilis; bacterial genetics; electron transport; enzyme complex; fusion gene; genetic translation; immunochemistry; membrane proteins; microorganism metabolism; molecular cloning; mutant; nucleic acid sequence; open reading frames; operon; posttranslational modifications; recombinant DNA; regulatory gene; respiratory oxygenation; sporogenesis; structural genes; transcription factor

Cytochrome aa3 is a multi-subunit enzyme complex that functions as a terminal oxidase in the respiratory chains of prokaryotic and eukaryotic cells. Although cytochrome aa3 has been well-studied biochemically, its genetic regulation is poorly understood. A number of hereditary human myopathies and encephalomyopathies have been traced to genes regulating formation of the mature complex. Molecular studies of cytochrome aa3 regulation are facilitated in bacteria because of its biochemical simplicity in these organisms. In addition, some bacteria contain variants of cytochrome aa3, for example caa3 or ba3, which because of unique characteristics can offer new insights into mechanism and regulation of the cytochrome aa3 family. This project addresses the regulation of cytochrome caa3 formation in Bacillus subtilis. The system has several attributes that make it particularly suitable: i) B. subtilis endospore formation is presently being described in molecular terms, ii) proper regulation of the respiratory chain is known to be critical to initiation of sporulation, iii) classical and molecular genetic technologies are well-developed; iv) B. subtilis is the only organism thus far shown to possess both cytochromes aa3 and caa3. Of particular importance are several regulatory genes identified in B. subtilis that affect cytochrome aa3 and caa3 formation. The structural genes for B. subtilis cytochrome caa3 (the ctaBCDEF cluster) recently have been cloned and sequenced. Physical, genetic, and transcriptional analyses are to be made of this cluster. Approaches will include integrational disruption, low- and high-resolution transcript mapping, and formation of gene fusions, a particular focus will be on the ctaA and strC gene products as possible transcriptional factors. The strC gene will be cloned for further study. Possibilities for participation of the ctaA and ctaB gene products in post-transcriptional regulation of cytochrome caa3 will be tested by immunochemical measurement of its subunits in ctaA and ctaB mutant backgrounds. The sca and scs suppressors of ctaA are to be studied genetically to gain insight into the functioning of these genes in the regulatory network that encompasses regulation of cytochrome aa3 and cytochrome caa3, as well as early events in the sporulation process.

细胞色素aa3是一种多亚单位酶复合体，其功能是 原核生物和真核生物呼吸链中的末端氧化酶 细胞。尽管细胞色素Aa3在生物化学方面已经得到了很好的研究，但它的 人们对基因调控知之甚少。一些遗传性人类 肌病和脑肌病被追溯到基因调控 形成成熟的复合体。细胞色素Aa3的分子研究 对细菌的调节是因为它的生物化学作用 这些有机体的简单性。此外，一些细菌还含有变种。 细胞色素Aa3，例如CaA3或Ba3，这是因为 特征可以为我们提供新的洞察机制和调节机制 细胞色素Aa3家族。这个项目涉及细胞色素的调节。 枯草芽孢杆菌CaA3的形成。该系统具有多个属性 这使得它特别适合：i)枯草杆菌内孢子形成 目前用分子术语描述，II)适当地调节 已知呼吸链是启动产孢子的关键， 三)经典和分子遗传技术发达；四) 到目前为止，枯草杆菌是唯一一种同时拥有这两种细胞色素的生物。 Aa3和Caa3。特别重要的是几个调控基因。 在枯草杆菌中鉴定出影响细胞色素Aa3和Caa3形成的物质。 枯草杆菌细胞色素Caa3(ctaBCDEF簇)的结构基因 最近都被克隆和测序。身体上、基因上和 将对这一簇进行转录分析。方法将 包括整合中断、低分辨率和高分辨率文字记录 基因融合的作图和形成，将特别关注 CtaA和strC基因产物可能是转录因子。StrC 该基因将被克隆以供进一步研究。参与的可能性 CtaA和CTAB基因产物在肿瘤细胞转录后调控中的作用 细胞色素CaA3将通过免疫化学方法检测其 CtaA和CTAB突变背景中的亚基。SCA和SCS抑制子 将对ctaA进行遗传学研究，以深入了解其功能 这些基因在包含调控的调控网络中 细胞色素Aa3和细胞色素Caa3以及早期事件 产孢子过程。