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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

An oxidation-sensing mechanism is used by the global regulator MgrA in Staphylococcus aureus

Peng R Chen1, Taeok Bae, Wade A Williams

  • 1Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA.

Nature Chemical Biology
|September 19, 2006
PubMed

Insights

Reactive oxygen species oxidize the Staphylococcus aureus MgrA protein, triggering antibiotic resistance. This study reveals MgrA

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Staphylococcus aureus is a major cause of wound and hospital-acquired infections.
  • The protein MgrA is crucial for virulence and antibiotic resistance in S. aureus.

Purpose of the Study:

  • To investigate the role of a unique cysteine residue in MgrA's function.
  • To elucidate the mechanism by which MgrA regulates antibiotic resistance in response to oxidative stress.

Main Methods:

  • Crystal structure determination of the MgrA homodimer at 2.86 A resolution.
  • Biochemical assays to assess the effect of reactive oxygen species on cysteine oxidation.
  • Analysis of MgrA's interaction with DNA and downstream signaling pathways.

Main Results:

  • A unique cysteine residue at the MgrA dimer interface was identified.
  • Cysteine oxidation by reactive oxygen species (e.g., hydrogen peroxide) was demonstrated.
  • Oxidation caused MgrA dissociation from DNA, initiating signaling pathways for antibiotic resistance.

Conclusions:

  • MgrA utilizes an oxidation-sensing mechanism to regulate defensive pathways in S. aureus.
  • This mechanism allows S. aureus to globally control responses to oxidative and nitrosative stress.
  • MgrA's cysteine residue is a key sensor for environmental challenges, impacting bacterial survival and pathogenesis.

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