Studies on the crystal structure of antiporters for organic compounds and the mechanisms

有机化合物反向转运蛋白的晶体结构及其机制研究

基本信息

批准号：
13142205
负责人：
YAMAGUCHI Akihito
金额：
$ 86.66万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2005
项目状态：
已结题

项目摘要

This project aimed for determination of the crystal structure of bacterial major xenobiotic exporter AcrB and to reveal the mechanism of xenobiotic recognition and efflux transport. Before this project, no crystal structures of membrane transporters had determined at all. Because the purpose of this project was highly riskful, at first we had one more target to determine two-dimensional structure of AcrB by using electron microscopic analysis as a risk hedge. However, as a result, the risk hedge was not required.Murakami et al. in our laboratory succeeded to determine the crystal structure of AcrB one year after starting this project. It is not only the first structure of xenobiotic exporters but also the first structure of the secondary transporters. This achievement is highly evaluated as a milestone of the membrane transport study. On the basis of this crystal structure, the xenobiotic recognition mechanism is clearly revealed: The AcrB structure has its entrance for substrates at t … More he side of the molecule opened to the lipid bilayer region of the membrane. AcrB acts as a membrane vacuum cleaner by taking up its substrates from the lipid bilayer region. Because xenobiotics generally enter into cells through lipid bilayer region by simple diffusion, this mechanism efficiently recognize xenobiotics.Our first structure did not contain bound substrate, therefore, it can not answer the question, "where is the binding site?". On the basis of the first structure, it was estimated as the central cavity of the trimer. One years after, Edward Yu et al. reported that the structure of AcrB in which substrates bound at the central cavity. However, this estimation was no consisted with the mutational studies; there is no amino acid residues important for substrate recognition at the central cavity.In the last year of this project, Murakami's group succeeded to determine the substrate binding structure of AcrB. The trimer is asymmetric. Only one protomer binds substrate at the phenylalanine cluster region, which is different from the central cavity. The other two porotmers represent the substrate extrusion step and the standing for substrate access step, respectively. In other words, this one crystal contains all snapshots for three steps of efflux transport. On the basis of this crystal structure, it was revealed that substrates are transported by the completely new mechanism named as functionally rotating binding change mechanism similar to FoF1-ATPase. In addition, it was revealed that the extraordinary broad substrate recognition is achieved by the multisite binding with mainly hydrophobic interactions. Less

该项目旨在确定细菌异生物出口商的aCRB，并揭示异源生物生物的机制和外排运输的机制。 - 使用电子显微镜分析作为一种风险对冲，我们的实验室中不需要危险。。通过从脂质双层区域取UTS底物的膜真空吸尘器。然而，在中心的腔体中，该项目的估计不包括突变的一年。与中央的挤压步骤不同，换句话说，换句话说。通过与Fof1-ATPase相似的全新机制，旋转的结合变化机制也揭示了非凡的宽底物识别。

项目成果

期刊论文数量（186）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

EvgA of the two-component signal transduction system modulates production of the YhiUV multidrug transporter in Escherichia coli

DOI：
10.1128/jb.184.8.2319-2323.2002
发表时间：
2002-04-01
期刊：
JOURNAL OF BACTERIOLOGY
影响因子：
3.2
作者：
Nishino, K;Yamaguchi, A
通讯作者：
Yamaguchi, A

Roles of To1C-dependent multidrug transporters of Escherichia col in resistance to beta-lactams

大肠杆菌To1C依赖性多药转运蛋白在β-内酰胺耐药中的作用

DOI：
发表时间：
2003
期刊：
Antimicrobial Agents and Chemotherapy 47
影响因子：
0
作者：
Kunihiko Nishino;Junko Yamada;Hidetada Hirakawa;Takahiro Hirata;Akihito Yamaguchi
通讯作者：
Akihito Yamaguchi

beta-Lactam resistance modulated by the overexpression o response regulators of two-component signal transduction systems in Escherichia coli

大肠杆菌中双组分信号转导系统的过度表达或反应调节因子调节β-内酰胺抗性

DOI：
发表时间：
2003
期刊：
Journal of Antimicrobial Chemotherapy 52
影响因子：
0
作者：
Hidetada Hirakawa;Kunihiko Nishino;Junko Yamada;Takahiro Hirata;Akihito Yamaguchi
通讯作者：
Akihito Yamaguchi

Indole induces the expression of multidrug exporter genes in Echerichia coli

吲哚诱导大肠杆菌多药输出基因的表达