MOLECULAR GENETICS OF BACILLUS SUBTILIS CYTOCHROME AA3

细胞色素aa 3是一种多亚基酶复合物， 原核生物和真核生物呼吸链末端氧化酶 细胞 虽然细胞色素aa 3已经在生物化学上得到了很好的研究， 基因调控知之甚少。 一些遗传性的人类 肌病和脑肌病的基因调控 形成成熟的复合体。 细胞色素aa 3的分子研究 由于其生物化学性质， 这些生物体的简单性。 此外，有些细菌含有变异体 细胞色素aa 3，例如caa 3或ba 3，由于其独特的 这些特征可以为研究细胞凋亡的机制和调控提供新的见解。 细胞色素aa 3家族 本项目涉及细胞色素的调节 枯草杆菌中caa 3的形成。 该系统有几个属性 使其特别适合：i）B.枯草芽孢杆菌内生孢子的形成是 目前以分子术语描述，ii）适当调节 已知呼吸链对孢子形成的起始是关键的， ㈢传统和分子遗传技术发展良好; ㈣ B。枯草芽孢杆菌是迄今为止唯一一种同时具有两种细胞色素的生物 AA 3和CAA 3。 特别重要的是几个调控基因 在B中标识。枯草杆菌影响细胞色素AA 3和CAA 3的形成。 B的结构基因枯草杆菌细胞色素caa 3（ctaBCDEF簇） 最近被克隆并测序了。 生理的，遗传的， 对该簇进行转录分析。 方法将 包括整合破坏、低分辨率和高分辨率转录本 映射，并形成基因融合，一个特别的重点将是对 ctaA和strC基因产物作为可能的转录因子。 strC 基因将被克隆用于进一步的研究。 参加的可能性 ctaA和ctaB基因产物在转录后调控中的作用 细胞色素CaA 3将通过免疫化学测量其 ctaA和ctaB突变体背景中的亚基。 sca和scs抑制因子 ctaA的基因将被研究，以深入了解功能 这些基因在调控网络中的作用， 细胞色素aa 3和细胞色素caa 3，以及早期事件， 孢子形成过程

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.