Study reveals how bacterial sensor protein detects and responds to beta-lactam antibiotics
Researchers discovered that the bacterial protein VbrK detects beta-lactam antibiotics through a redox-dependent mechanism involving cysteine acylation, a previously unknown sensing pathway in gram-negative bacteria. The sensor's ability to recognize beta-lactams depends on the redox state of specific cysteines and involves covalent modification followed by slow de-acylation. This discovery could help prevent antibiotic resistance by identifying new targets to block resistance-activation systems.
A bioRxiv preprint describes how Vibrio parahaemolyticus, a gram-negative pathogen, senses beta-lactam antibiotics through its VbrK/VbrR two-component system. The research reveals that beta-lactam binding to VbrK's periplasmic sensor domain depends critically on the redox state of two cysteine residues (C86 and C107), with disulfide bond dynamics playing a key regulatory role. The interaction triggers acylation of the sensor domain by the beta-lactam molecule itself, a covalent modification that is slowly reversed through de-acylation once the antibiotic is depleted. This redox- and covalent chemistry-dependent mechanism represents a previously unrecognized mode of antibiotic detection in bacteria. The findings provide a molecular framework for understanding how this sensing system activates resistance responses and suggest new strategies for preventing antibiotic resistance by targeting these resistance-activation pathways.
Limitations & open questions
The study's own limitations and open questions are not detailed in the abstract provided. Additionally, the practical implications for developing resistance-blocking therapeutics and the timeline for translating these findings into clinical applications remain unspecified.
What different sources said
- bioRxivCenter
Redox-regulated cysteine acylation governs β-lactam sensing by the Vibrio histidine kinase VbrK
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