2HQG

Conformation of the AcrB Multidrug Efflux Pump in Mutants of the Putative Proton Relay Pathway

2HQG の概要

• エントリーDOI: 10.2210/pdb2hqg/pdb
• 関連するPDBエントリー: 1T9T 2HQC 2HQD 2HQF
• 分子名称: Acriflavine resistance protein B (1 entity in total)
• 機能のキーワード: membrane protein, multidrug efflux pump
• 由来する生物種: Escherichia coli K12
• 細胞内の位置: Cell inner membrane ; Multi- pass membrane protein : P31224
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 114187.73

構造登録者

Su, C.-C.,Li, M.,Gu, R.,Takatsuka, Y.,McDermott, G.,Nikaido, H.,Yu, E.W. (登録日: 2006-07-18, 公開日: 2007-04-17, 最終更新日: 2024-02-14)

主引用文献

Su, C.-C.,Li, M.,Gu, R.,Takatsuka, Y.,McDermott, G.,Nikaido, H.,Yu, E.W.
Conformation of the AcrB multidrug efflux pump in mutants of the putative proton relay pathway
J.Bacteriol., 188:7290-7296, 2006

PubMed Abstract: We previously reported the X-ray structures of wild-type Escherichia coli AcrB, a proton motive force-dependent multidrug efflux pump, and its N109A mutant. These structures presumably reflect the resting state of AcrB, which can bind drugs. After ligand binding, a proton may bind to an acidic residue(s) in the transmembrane domain, i.e., Asp407 or Asp408, within the putative network of electrostatically interacting residues, which also include Lys940 and Thr978, and this may initiate a series of conformational changes that result in drug expulsion. Herein we report the X-ray structures of four AcrB mutants, the D407A, D408A, K940A, and T978A mutants, in which the structure of this tight electrostatic network is expected to become disrupted. These mutant proteins revealed remarkably similar conformations, which show striking differences from the previously known conformations of the wild-type protein. For example, the loop containing Phe386 and Phe388, which play a major role in the initial binding of substrates in the central cavity, becomes prominently extended into the center of the cavity, such that binding of large substrate molecules may become difficult. We believe that this new conformation may mimic, at least partially, one of the transient conformations of the transporter during the transport cycle.

PubMed: 17015668
DOI: 10.1128/JB.00684-06

実験手法

X-RAY DIFFRACTION (3.38 Å)