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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
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The CsoR-like sulfurtransferase repressor (CstR) is a persulfide sensor in Staphylococcus aureus
Justin L Luebke1, Jiangchuan Shen, Kevin E Bruce
1Department of Chemistry, Indiana University, Bloomington, IN, 47405-7102, USA.
Molecular Microbiology
|October 17, 2014
Summary
Staphylococcus aureus uses the cst operon to manage sulfide toxicity. Its repressor, CstR, is modified by persulfides, inhibiting gene expression and maintaining sulfur homeostasis.
Area of Science:
- Microbiology
- Biochemistry
- Cellular Biology
Background:
- Cellular sulfur metabolism and hydrogen sulfide toxicity are critical but poorly understood.
- CstR (Copper-sensing operon repressor-like sulfurtransferase repressor) regulates the cst operon for sulfide oxidation in Staphylococcus aureus.
Purpose of the Study:
- To investigate the role of the cst operon and CstR in Staphylococcus aureus's response to sulfide stress.
- To elucidate the mechanism by which CstR regulates cst operon expression.
Main Methods:
- Bacterial growth assays in various media (chemically defined, rich).
- Genetic manipulation (ΔcstR strain, CstR mutants).
- Tandem high-resolution mass spectrometry to analyze CstR modifications.
Main Results:
- The cst operon is rapidly induced by sulfide stress and essential for mitigating toxicity.
- S. aureus growth is impaired without functional CstR or cst operon induction.
- CstR is modified by inorganic tetrasulfide and glutathione persulfide, forming interprotomer cross-links.
- These modifications allosterically inhibit CstR's DNA binding, repressing cst operon expression.
Conclusions:
- The cst operon and its repressor CstR are crucial for maintaining sulfur homeostasis and preventing sulfide toxicity in S. aureus.
- Sulfide-induced modification of CstR is a key regulatory mechanism controlling the expression of the sulfide oxidation system.
