MOLECULAR ANALYSIS OF FERRIC ENTEROBACTIN TRANSPORT

三价肠杆菌素转运的分子分析

• 批准号: 2180435
• 负责人: MARK A MCINTOSH
• 金额: $ 11.03万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2180435
• 关键词: Escherichia coli; active transport; binding proteins; chimeric proteins; enzyme complex; enzyme mechanism; gene expression; gram negative bacteria; iron metabolism; iron sulfur protein; laboratory mouse; membrane proteins; microorganism metabolism; mutant; nucleic acid sequence; protein biosynthesis; protein transport; receptor; siderophores; structural genes

Active transport of required metabolites in gram negative organisms is the result of complex interactions between cellular constituents localized in the outer and cytoplasmic membranes and the periplasmic space. The overall objectives of our research plan are to develop a model transport system in which these interactions may be probed. In particular, this proposal is designed to delineate structural and functional features of three specific Escherichia coli proteins involved in the biosynthesis (EntD) of the catechol siderophore enterobactin (enterochelin) and the siderophore-mediated uptake (FepA, Fes) of the nutritionally important trace element, iron. The structural genes for these three components have been isolated and their nucleotide sequences determined. The protein products have been identified and in come cases purified. In vitro and in vivo mutagenesis procedures along with protein biochemistry protocols will be employed to evaluate structural and functional features of: (1) the outer membrane receptor (FebA) binding sites for its three specific ligands, ferric enterobactin, colicin D and colicin B; (2) the cytoplasmic enzyme Fes, which is responsible for removing iron from the siderophore complex upon its entry into the cell; and (3) the membrane-associated biosynthetic enzyme EntD, including the nature of its molecular association with the other components (EntE, EntF and EntG) of the multienzyme complex enterobactin synthetase, and its potential role in extracellular release of newly synthesized siderophore molecules. Aside from its basic scientific interest as a model high affinity transport system, an understanding of the mechanisms of iron transport is significant is that in all organisms studied, from bacterial to man, the metabolic iron state of the organism regulates the degree of nutritive iron absorption and iron has been documented as an important factor of the pathophysiology of disseminating gram negative infections in man and animals. It is hoped that this system may present a model defining the essential characteristics of iron transport for comparison with similar systems from other gram negative pathogens and against which effective future therapies may be targeted.

在革兰氏阴性生物中，主动运输所需的代谢产物是 细胞成分之间复杂相互作用的结果 位于外部和细胞质膜以及周质膜中 空间。 我们研究计划的总体目标是制定 可以探测这些相互作用的模型传输系统。 在 特别是，该建议旨在描述结构和 涉及三个特定大肠杆菌蛋白的功能特征 在Catechol Siderophore Enterobactin的生物合成（ENTD）中 （Enterochelin）和铁载体介导的摄取（FEPA，FES） 营养重要的痕量元素，铁。 结构基因 这三个成分已经分离出来，其核苷酸序列 决定。蛋白质产品已被鉴定出来，并在发生情况下 纯化。 体外和体内诱变程序以及蛋白 生物化学方案将用于评估结构和 功能特征：（1）外膜受体（FEBA）结合 其三种特定配体的位点，铁肠霉素，结菌素D和 Colicin b; （2）细胞质酶FES，该酶负责 进入细胞时从铁载体复合物中去除铁； （3）膜相关的生物合成酶entd，包括 其分子与其他成分的分子关联的性质（Ente，ENTF 和多烯酶复合物肠乳糖蛋白合成酶的ENTG及其 在新合成的铁载体的细胞外释放中的潜在作用 分子。 除了其作为模型高亲和力的基本科学兴趣之外 运输系统，对铁运输机制的理解是 重要的是，在所有研究的生物中，从细菌到人， 有机体的代谢铁状态调节营养的程度 铁吸收和铁已被记录为 传播革兰氏阴性感染的病理生理和 动物。 希望该系统可以提出一个定义的模型 铁运输的基本特征，以与类似 来自其他革兰氏阴性病原体的系统，有效 未来的疗法可能是针对目标的。

项目成果

Epitope insertions define functional and topological features of the Escherichia coli ferric enterobactin receptor.

表位插入定义了大肠杆菌铁肠杆菌素受体的功能和拓扑特征。

• DOI: 10.1074/jbc.270.6.2483
• 发表时间: 1995
• 期刊: The Journal of biological chemistry
• 作者: Armstrong,SK;McIntosh,MA
• 通讯作者: McIntosh,MA

Molecular analysis of the Escherichia coli ferric enterobactin receptor FepA.

• DOI: 10.1016/s0021-9258(18)77336-5
• 发表时间: 1990-08
• 期刊: The Journal of biological chemistry
• 作者: Sandra K. Armstrong;Carol L. Francis;Carol L. Francis;Mark A. McIntosh

Formation of a gated channel by a ligand-specific transport protein in the bacterial outer membrane.

细菌外膜中配体特异性转运蛋白形成门控通道。

• DOI: 10.1126/science.1411544
• 发表时间: 1992
• 期刊: Science (New York, N.Y.)
• 作者: Rutz,JM;Liu,J;Lyons,JA;Goranson,J;Armstrong,SK;McIntosh,MA;Feix,JB;Klebba,PE
• 通讯作者: Klebba,PE