Cytochrome c biogenesis

细胞色素c生物合成

• 批准号: 6546941
• 负责人: Robert G. Kranz
• 金额: $ 33.25万
• 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/6546941
• 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无氧电子传输所必需的血红素蛋白。虽然许多这些蛋白质的结构和功能已经被研究了五十多年，但直到最近才清楚细胞色素通常需要组装因子。此类组装因子在某些人类疾病中存在缺陷，但对于许多病原体的生长至关重要。 c型细胞色素的生物合成需要大量因素，并且可以通过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，预计这两种系统都需要专门的机制来进行血红素输送和脱辅基细胞色素硫醇还原。在真菌、无脊椎动物和脊椎动物的线粒体中专门进化的系统 III 中，线粒体膜间隙中一种称为细胞色素 c 血红素裂解酶的酶发挥着关键作用。 细胞色素 c 的生物发生需要系统 I 的九种专用完整膜蛋白，系统 II 的至少三种膜蛋白。该提案的目标是了解系统 I 和 II 使用三种模型变形菌、荚膜红杆菌（系统 I）、百日咳博德特氏菌（系统 II）和大肠杆菌（系统 I 和重组系统 II）运作的分子机制。具体来说，目标是 (1) 鉴定和表征百日咳博德特氏菌中新的 System II 基因； (2) 使用系统 I 和系统 II 重建体外生物发生； (3)确定系统I和II的底物识别要求(即脱辅基和血红素)和必要的生理条件； (4)对系统I和II涉及的关键蛋白进行功能分析。