title: Crystallographic analysis of AcrB.
abstract: A His-tagged derivative of the multidrug efflux pump AcrB could be crystallized in three different space groups (R3, R32 and P321). Experimental MAD-phasing maps from R32 AcrB(His) crystals were obtained to a resolution of 3.5 A. Datasets of native and substrate soaked AcrB(His) crystals were collected at the Swiss Light Source X06SA beamline up to a resolution of 2.7 A and refinement of these data provided good quality electron density maps, which allowed us to complement the published AcrB structure (PDB code 1iwg). Introduction of amino acids 860-865 and 868 lacking in the 1iwg structure and deletion of a highly disordered region (amino acids 669-678) improved R(free) and average B factors in the 2.7 A model. We could not identify significant densities indicating specific antibiotic binding sites in the AcrB R32 space group datasets under the soaking conditions tested.
authors.affiliation: Institut für Mikrobiologie, D-Biol, ETH Zürich, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland. pos@micro.biol.ethz.ch
authors.forename: Klaas M
authors.initials: KM
authors.lastname: Pos
authors.forename: André
authors.initials: A
authors.lastname: Schiefner
authors.forename: Markus A
authors.initials: MA
authors.lastname: Seeger
authors.forename: Kay
authors.initials: K
authors.lastname: Diederichs
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000737:chemistry / Q000187:drug effects; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D015394:Molecular Structure; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011485:Protein Binding; D020836:Protein Structure, Quaternary
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083496:AcrB protein, E coli