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Updated: Jun 8, 2026

Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein
10:43

Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein

Published on: December 3, 2010

LmrS is a multidrug efflux pump of the major facilitator superfamily from Staphylococcus aureus

Jody L Floyd1, Kenneth P Smith, Sanath H Kumar

  • 1Eastern New Mexico University, Department of Biology, Station 33, Portales, NM 88130, USA.

Antimicrobial Agents and Chemotherapy
|September 22, 2010
PubMed

Insights

A novel multidrug efflux pump, LmrS, was identified in Staphylococcus aureus. This transporter confers resistance to critical antibiotics like linezolid and trimethoprim.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Multidrug efflux pumps are crucial in antimicrobial resistance.
  • The major facilitator superfamily (MFS) includes many clinically relevant transporters.
  • Staphylococcus aureus possesses various resistance mechanisms, including efflux pumps.

Purpose of the Study:

  • To clone and characterize a novel multidrug efflux pump, LmrS, from Staphylococcus aureus.
  • To evaluate the role of LmrS in the efflux of various antimicrobial agents.
  • To determine the substrate specificity of the LmrS transporter.

Main Methods:

  • Cloning of the LmrS gene from Staphylococcus aureus.
  • Determination of minimum inhibitory concentrations (MICs) for various compounds in the presence and absence of LmrS.
  • Bioinformatic analysis to predict the structure and homology of LmrS.

Main Results:

  • The LmrS efflux pump was successfully cloned and expressed.
  • LmrS conferred a significant increase in MIC values for linezolid (16-fold) and tetraphenylphosphonium chloride (TPCL) (16-fold).
  • Increased resistance was also observed for sodium dodecyl sulfate (SDS), trimethoprim, and chloramphenicol (8-fold).

Conclusions:

  • LmrS is a functional multidrug efflux pump belonging to the MFS transporter family.
  • LmrS contributes to Staphylococcus aureus resistance against clinically important antibiotics and biocides.
  • LmrS exhibits homology to lincomycin resistance proteins in other bacterial species, suggesting conserved resistance mechanisms.

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