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An O2-sensing stressosome from a Gram-negative bacterium
Xin Jia1, Jian-Bo Wang1, Shannon Rivera1
1Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, USA.
Nature Communications
|August 5, 2016
Summary
Researchers identified a novel bacterial stressosome in Gram-negative bacteria. This stressosome, regulated by haem binding to RsbR, suggests activation during anaerobic conditions, offering insights into bacterial stress response.
Area of Science:
- Microbiology
- Bacterial Physiology
- Signal Transduction
Background:
- Gram-positive bacteria utilize stressosome complexes to regulate general stress response genes.
- The signaling molecules recognized by Gram-positive stressosomes remain unidentified.
- Analogous pathways in Gram-negative bacteria are largely undescribed.
Purpose of the Study:
- To characterize a putative stressosome complex in the Gram-negative bacterium Vibrio brasiliensis.
- To elucidate the ligand-dependent signaling mechanism of this novel stressosome.
- To investigate the role of oxygen in regulating stressosome activity.
Main Methods:
- Biochemical characterization of the sensor protein RsbR.
- Analysis of haem binding and its effect on stressosome activity.
- Investigating ligand-dependent control of the stressosome complex.
Main Results:
- The sensor protein RsbR binds haem and exhibits ligand-dependent activity.
- Oxygen binding to RsbR decreases stressosome activity.
- Ferrous RsbR binding increases stressosome activity, suggesting activation under anaerobic conditions.
Conclusions:
- The Vibrio brasiliensis stressosome provides a model for studying ligand-dependent signaling in stressosome complexes.
- Findings suggest the V. brasiliensis stressosome is activated during anaerobic growth.
- This research offers insights into oxygen-dependent signaling pathways in Vibrio species.
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