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Attraction by repellents: an error in sensory information processing by bacterial mutants
Science (New York, N.Y.)
|July 7, 1978
Summary
Researchers identified Escherichia coli mutants with reversed chemotaxis, showing attraction to repellents like acetate and repulsion from attractants like alpha-aminoisobutyrate. These mutants are defective in methylated chemosensory proteins (MCPs), altering bacterial movement.
Area of Science:
- Microbiology
- Bacterial Physiology
- Chemotaxis Research
Background:
- Escherichia coli exhibits specific chemotaxis, being repelled by acetate, benzoate, and indole, while attracted to alpha-aminoisobutyrate.
- Chemotaxis is crucial for bacterial survival, guiding movement towards favorable environments and away from harmful substances.
Purpose of the Study:
- To investigate the genetic basis of reversed chemotaxis in Escherichia coli.
- To identify the molecular components responsible for altered bacterial responses to chemical stimuli.
Main Methods:
- Isolation and characterization of bacterial mutants with reversed taxis.
- Analysis of defects in key signaling pathways, specifically methylated chemosensory proteins (MCPs).
Main Results:
- Successfully isolated mutants exhibiting attraction to previously repellent substances (acetate, benzoate, indole) and repulsion from an attractant (alpha-aminoisobutyrate).
- Identified that these reversed-taxis mutants possess defects in a central processing component involving methylated chemosensory proteins (MCPs).
Conclusions:
- Methylated chemosensory proteins (MCPs) play a critical role in mediating the direction of chemotaxis in Escherichia coli.
- Mutations in MCPs can lead to a reversal of normal taxis responses, providing insights into the molecular mechanisms of bacterial navigation.