View source for 1t9u


==Structural Basis of Multidrug Transport by the AcrB Multidrug Efflux Pump==
<StructureSection load='1t9u' size='340' side='right'caption='[[1t9u]], [[Resolution|resolution]] 3.11&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1t9u]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T9U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1T9U FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.11&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CPF:1-CYCLOPROPYL-6-FLUORO-4-OXO-7-PIPERAZIN-1-YL-1,4-DIHYDROQUINOLINE-3-CARBOXYLIC+ACID'>CPF</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1t9u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1t9u OCA], [https://pdbe.org/1t9u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1t9u RCSB], [https://www.ebi.ac.uk/pdbsum/1t9u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1t9u ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ACRB_ECOLI ACRB_ECOLI] AcrAB is a drug efflux protein with a broad substrate specificity.<ref>PMID:16915237</ref> <ref>PMID:16946072</ref> <ref>PMID:17194213</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/t9/1t9u_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1t9u ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
The Escherichia coli AcrB multidrug efflux pump is a membrane protein that recognizes many structurally dissimilar toxic compounds. We previously reported the X-ray structures of four AcrB-ligand complexes in which the ligands were bound to the wall of the extremely large central cavity in the transmembrane domain of the pump. Genetic studies, however, suggested that discrimination between the substrates occurs mainly in the periplasmic domain rather than the transmembrane domain of the pump. We here describe the crystal structures of the AcrB mutant in which Asn109 was replaced by Ala, with five structurally diverse ligands, ethidium, rhodamine 6G, ciprofloxacin, nafcillin, and Phe-Arg-beta-naphthylamide. The ligands bind not only to the wall of central cavity but also to a new periplasmic site within the deep external depression formed by the C-terminal periplasmic loop. This depression also includes residues identified earlier as being important in the specificity. We show here that conversion into alanine of the Phe664, Phe666, or Glu673 residue in the periplasmic binding site produced significant decreases in the MIC of most agents in the N109A background. Furthermore, decreased MICs were also observed when these residues were mutated in the wild-type AcrB background, although the effects were more modest. The MIC data were also confirmed by assays of ethidium influx rates in intact cells, and our results suggest that the periplasmic binding site plays a role in the physiological process of drug efflux.

A periplasmic drug-binding site of the AcrB multidrug efflux pump: a crystallographic and site-directed mutagenesis study.,Yu EW, Aires JR, McDermott G, Nikaido H J Bacteriol. 2005 Oct;187(19):6804-15. PMID:16166543<ref>PMID:16166543</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1t9u" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: McDermott G]]
[[Category: Nikaido H]]
[[Category: Yu EW]]