Export & Import of Lethal Agents Mediated by TolC

出口

基本信息

批准号：
7104845
负责人：
RAJEEV MISRA
金额：
$ 21.04万
依托单位：
ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-08-05 至 2009-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7104845
关键词：
Escherichia coli antibacterial agents antibody bacterial genetics bacterial proteins bacterial toxins colicines immunologic substance development /preparation laboratory rabbit membrane permeability membrane transport proteins mutant protein protein interaction protein structure function protein transport

项目摘要

DESCRIPTION (provided by applicant): Transport of molecules across biological membranes is a fundamental process shared by all living cells. In Gram-negative bacteria, such as Escherichia coil, transport occurs across two membranes, of which the outer membrane represents the first permeability barrier. Outer membrane protein-mediated transport is needed to bring nutrients inside and expel unwanted metabolites and inhibitors. Ironically, toxic biomolecules and infectious agents, present in the hostile environment in which bacteria live, frequently exploit these outer membrane proteins to gain entry into the cell. The focus of this research is a unique outer membrane protein, TolC, which mediates the diffusion of a diverse group of molecules including the export of alpha-hemolysin and the efflux of antibiotics. Despite the resolution of TolC's three-dimensional structure, the role of individual residues and the mechanism by which it accomplishes the transport of a diverse group of molecules remains poorly understood. Moreover, it is unknown how TolC interacts with other proteins of the inner membrane to form the complexes that facilitate the two-way transport activity. The present study is being undertaken to examine the role of TolC in export (antibiotic) and import (colicin E1 ), as well as to examine its interactions with other proteins of the transport complexes. Identification of functionally critical TolC residues and the various protein-protein interactions that must occur to accomplish the diverse transport activities will be achieved through employing a combination of genetic, structural, and biochemical approaches; available preliminary data concerning all aspects of the project strongly reflect their feasibility.The presence of TolC and its homologues in other Gram-negative bacteria demonstrates the broader relevance of this unique multifunctional protein. Besides the obvious role of TolC in antibiotic resistance, its ability to mediate the secretion of a variety of virulence factors in pathogenic bacteria makes it a medically important subject of investigation.

描述（由申请人提供）：分子跨生物膜的运输是所有活细胞共享的一个基本过程。在革兰氏阴性细菌（例如埃舍里希亚线圈）中，运输发生在两个膜上，其中外膜代表了第一个渗透性屏障。需要外膜蛋白介导的转运来将营养物质带入其中并驱除不需要的代谢物和抑制剂。具有讽刺意味的是，在细菌生存的敌对环境中存在有毒的生物分子和传染剂，经常利用这些外膜蛋白进入细胞。这项研究的重点是独特的外膜蛋白TOLC，它介导了各种分子的扩散，包括α-溶血素的出口和抗生素外排。尽管解决了TOLC的三维结构，但单个残基的作用及其完成多种分子的运输机制的作用仍然很少了解。此外，尚不清楚Tolc如何与内膜的其他蛋白质相互作用，以形成促进双向运输活性的复合物。本研究正在进行研究TOLC在出口（抗生素）和进口（Colicin E1）中的作用，并检查其与运输复合物其他蛋白质的相互作用。通过采用遗传，结构和生化方法的组合来实现功能上关键的TOLC残基和必须实现多种运输活性的各种蛋白质蛋白相互作用的鉴定；有关该项目的各个方面的可用初步数据强烈反映了它们的可行性。TOLC的存在及其在其他革兰氏阴性细菌中的同源物的存在表明了这种独特的多功能蛋白质的广泛相关性。除了TOLC在抗生素耐药性中的明显作用外，其介导多种毒力因子在致病细菌中分泌的能力使其成为医学上重要的研究主题。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Genetic assessment of the role of AcrB β-hairpins in the assembly of the TolC-AcrAB multidrug efflux pump of Escherichia coli.

DOI：
10.1111/mmi.12508
发表时间：
2014-03
期刊：
Molecular microbiology
影响因子：
3.6
作者：
Weeks JW;Bavro VN;Misra R
通讯作者：
Misra R

Assembly and channel opening in a bacterial drug efflux machine.

DOI：
10.1016/j.molcel.2008.02.015
发表时间：
2008-04-11
期刊：
MOLECULAR CELL
影响因子：
16
作者：
Bavro, Vassiliy N.;Pietras, Zbigniew;Furnham, Nicholas;Perez-Cano, Laura;Fernandez-Recio, Juan;Pei, Xue Yuan;Misra, Rajeev;Luisi, Ben
通讯作者：
Luisi, Ben

AcrA suppressor alterations reverse the drug hypersensitivity phenotype of a TolC mutant by inducing TolC aperture opening.