Cytochrome c biogenesis

细胞色素c生物合成

• 批准号: 6663173
• 负责人: Robert G. Kranz
• 金额: $ 31.67万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6663173
• 关键词: Bordetella pertussis; Escherichia coli; Rhodospirillales; apoenzymes; bacterial genetics; bacterial proteins; cytochrome c; cytochrome c peroxidase; disulfide bond; enzyme activity; gene deletion mutation; genetic screening; hemoprotein biosynthesis; immunoprecipitation; laboratory rabbit; lyase; mass spectrometry; molecular assembly /self assembly; mutant; plasmids; porphyrins; protein purification; protein reconstitution; protein structure function; transfection /expression vector

DESCRIPTION (provided by applicant): Cytochromes are heme proteins essential for aerobic and anaerobic electron transport in most organisms. While the structures and functions of many of these proteins have been studied for over fifty years, only relatively recently has it become clear that cytochromes often require assembly factors. Such assembly factors are defective in certain human disorders, and essential for growth in many pathogens. Biogenesis of the c-type cytochromes requires a large number of factors and can proceed by any one of three systems. Prokaryotes, plant mitochondria, and chloroplasts use either system I or II, which are each predicted to require dedicated mechanisms for heme delivery and apocytochrome thiolreduction. In system III, which has specifically evolved in the mitochondna of fungi, invertebrates, and vertebrates, a pivotal role is played by a single enzyme called cytochrome c heme lyase in the mitochondrial intermembrane space. Cytochrome c biogenesis requires nine dedicated, integral membrane proteins for System I and at least three for System II. The goals of this proposal are to understand the molecular mechanisms by which Systems I and II operate using three model proteobacteria, Rhodobacter capsulatus (System I), Bordetella pertussis (System II), and Escherichia coli (System I and recombinant System II). Specifically, aims are to (1) identify and characterize novel System II genes in B. pertussis; (2) reconstitute in vitro biogenesis using System I and System II; (3) determine the substrate recognition requirements (ie. apocytocbrome and heme) and the physiological conditions essential for System I and II; (4) carry out a functional analysis of key proteins involved in System I and II.

描述（由申请人提供）：细胞色素是大多数生物体中有氧和厌氧电子转运必不可少的血红素蛋白。尽管已经研究了许多这些蛋白质的结构和功能已有五十多年了，但只有最近才清楚地表明，细胞色素通常需要装配因子。这种装配因子在某些人类疾病中有缺陷，对于许多病原体的生长至关重要。 C型细胞色素的生物发生需要大量因素，并且可以由三个系统中的任何一种进行。原核生物，植物线粒体和叶绿体使用系统I或II，每个系统都需要专门的机制来进行血红素递送和apocytochrome硫代硫醇。在系统III中，它是在真菌，无脊椎动物和脊椎动物的线粒体中特异性进化的，在线粒体膜间空间中，一种称为细胞色素c Heme裂解酶的单个酶发挥了关键作用。 细胞色素C生物发生需要9个专用的，整体的膜蛋白，用于系统I，至少三个用于系统II。该提案的目标是了解系统I和II使用三种模型蛋白细菌，Rhodobacter capsulatus（System I），Bordetella tussis（System II）和Escherichia Coli（系统I和重组系统II）运行的分子机制。具体而言，目的是（1）识别和表征百日咳芽孢杆菌中新型System II基因； （2）使用系统I和系统II重新构建体外生物发生； （3）确定底物识别要求（即启示膜和血红素），以及系统I和II所必需的生理条件； （4）对系统I和II涉及的关键蛋白进行功能分析。