title: The SMR family: a novel family of multidrug efflux proteins involved with the efflux of lipophilic drugs.
abstract: The sequenced members of a novel family of small, hydrophobic, bacterial multidrug-resistance efflux proteins, which we have designated the small multidrug resistance (SMR) protein family, are identified and analysed. Two distinct clusters of proteins were identified within this family: (i) small multidrug efflux systems; and (ii) Sug proteins, potentially involved in the suppression of groEL mutations. Hydropathy and residue distribution analyses of this family suggest a structural model in which the polypeptide chain spans the membrane four times as mildly amphipathic alpha-helices. The roles of specific residues, a possible mechanistic model of drug efflux, and the primary physiological role(s) of the SMR proteins are discussed.
authors.affiliation: School of Biological Sciences, University of Sydney, Australia.
authors.forename: I T
authors.initials: IT
authors.lastname: Paulsen
authors.forename: R A
authors.initials: RA
authors.lastname: Skurray
authors.forename: R
authors.initials: R
authors.lastname: Tam
authors.forename: M H
authors.initials: MH
authors.lastname: Saier
authors.forename: R J
authors.initials: RJ
authors.lastname: Turner
authors.forename: J H
authors.initials: JH
authors.lastname: Weiner
authors.forename: E B
authors.initials: EB
authors.lastname: Goldberg
authors.forename: L L
authors.initials: LL
authors.lastname: Grinius
mesh_terms: D000595:Amino Acid Sequence; D017920:Antiporters; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001693:Biological Transport, Active; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D018432:Drug Resistance, Multiple; D029968:Escherichia coli Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
chemical_list: D017920:Antiporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010455:Peptides; C075436:EmrE protein, E coli