title: Sequence of a class E tetracycline resistance gene from Escherichia coli and comparison of related tetracycline efflux proteins.
abstract: We determined the nucleotide sequence of the class E tetA gene on plasmid pSL1456 from Escherichia coli SLH1456A. The deduced amino acid sequence of the class E TetA protein shows 50 to 56% identity with the sequences of five related TetA proteins (classes A through D and G). Hydrophobicity profiles identify 12 putative transmembrane segments with similar boundaries in all six TetA sequences. The N-terminal alpha domain of the six sequences is more highly conserved than the C-terminal beta domain; the central hydrophilic loop connecting the alpha and beta domains is the least conserved region. Amino acid residues that have been shown to be important for class B (Tn10) TetA function are conserved in all six TetA sequences. Unlike the class B tetA gene, the class D and E tetA genes do not exhibit a negative gene dosage effect when present on multicopy plasmids derived from pACYC177.
authors.affiliation: Department of Microbiology, Washington State University, Pullman 99164.
authors.forename: J D
authors.initials: JD
authors.lastname: Allard
authors.forename: K P
authors.initials: KP
authors.lastname: Bertrand
mesh_terms: D000595:Amino Acid Sequence; D017920:Antiporters; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D013753:Tetracycline Resistance / Q000235:genetics*
chemical_list: D017920:Antiporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; C079051:tetA protein, Bacteria