Emr, an Escherichia coli locus for multidrug resistance - PubMed (original) (raw)

Comparative Study

Emr, an Escherichia coli locus for multidrug resistance

O Lomovskaya et al. Proc Natl Acad Sci U S A. 1992.

Abstract

An Escherichia coli chromosomal DNA fragment cloned on a multicopy plasmid conferred resistance to carbonylcyanide m-chlorophenylhydrazone, nalidixic acid, and a number of other toxic compounds. The sequence of the cloned emr locus located at minute 57.5 of the chromosome revealed two open reading frames, emrA and emrB. emrB encodes a highly hydrophobic 56.2-kDa peptide, with 14 potential alpha-helices to span the inner membrane. The peptide is homologous to QacA, a multidrug-resistant pump from Staphylococcus aureus, and belongs to a gene family that includes tetracycline-resistant pumps of Gram-positive bacteria and the galactose/H+ symporter of E. coli. emrA encodes a putative 42.7-kDa peptide containing a single hydrophobic domain and a large C-terminal hydrophilic domain. An active pho-fusion to the C domain suggested that EmrA is a membrane protein. Disruption of emrB significantly increased sensitivity of cells to uncouplers. The cellular content of uncoupler increased in the order: overexpressed emrB cells greater than wild type greater than emrB-.

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References

    1. Antimicrob Agents Chemother. 1992 Apr;36(4):695-703 - PubMed
    1. J Bacteriol. 1982 Feb;149(2):758-67 - PubMed
    1. Plasmid. 1992 Mar;27(2):119-29 - PubMed
    1. Methods Enzymol. 1991;204:139-80 - PubMed
    1. Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4781-5 - PubMed

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