title: Transmembrane helix 12 of the Staphylococcus aureus multidrug transporter QacA lines the bivalent cationic drug binding pocket.
abstract: An acidic residue in transmembrane segment (TMS) 10 is important for recognition of bivalent cationic substrates by the QacA multidrug transporter. Remarkably, an acidic residue in TMS 12 compensated for the absence of such a residue in TMS 10, suggesting that TMS 12 is a component of the bivalent cation-binding region.
authors.affiliation: School of Biological Sciences, The University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Karl A
authors.initials: KA
authors.lastname: Hassan
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Skurray
authors.forename: Melissa H
authors.initials: MH
authors.lastname: Brown
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002413:Cations, Divalent / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002413:Cations, Divalent; D026901:Membrane Transport Proteins; C068498:qacA protein, Staphylococcus aureus