Bacterial Chemotaxis Signal Transduction Systems

Bacterial chemotaxis signal transduction systems enable motile bacteria to navigate chemical gradients in their environments, directing movement towards attractants and away from repellents. Core components typically include transmembrane chemoreceptors that detect extracellular ligands, the histidine kinase CheA, the coupling protein CheW, and the response regulator CheY. Ligand binding to receptor sensory domains modulates CheA autophosphorylation, transferring the phosphoryl group via CheY to the flagellar motor, thereby altering the frequency of runs and tumbles. Adaptation is achieved through reversible modification of receptor methylation states by CheR methyltransferase and CheB methylesterase, restoring sensitivity over a wide dynamic range. Beyond the canonical two-component module, many species integrate additional layers of regulation involving second messengers such as cyclic di-GMP, chemosensory arrays whose supramolecular architecture amplifies signals, and alternative sensory domains that expand the repertoire of detectable stimuli. Chemotaxis underpins key behaviours from nutrient foraging and biofilm formation to host colonisation and interspecies interactions, reflecting its global significance in microbial ecology, pathogenesis and biotechnology.

Research from Nature Portfolio

Recent studies have uncovered previously unrecognised chemotactic signals and widespread sensor motifs. Work with Vibrio cholerae revealed that the d-amino acids d-arginine and d-lysine serve as repellent cues under stress conditions. A dedicated chemoreceptor, co-transcribed with the racemase enzyme that synthesises these d-amino acids, was structurally characterised in complex with its ligands, pinpointing key residues that define specificity and suggesting a role in shaping community structure under adverse conditions. In parallel, structural and bioinformatic analyses have defined a purine-binding motif conserved across thousands of bacterial receptors that modulate motility, gene expression and second-messenger turnover. Biophysical validation demonstrated specific binding to purine derivatives, and functional assays showed that this sensor family feeds into cyclic di-GMP signalling, linking purine availability to broad physiological responses.

Bacterial Chemotaxis Signal Transduction Systems publication trend

The graph below shows the total number of articles in bacterial chemotaxis signal transduction systems across all publications each year (not limited to Nature Index journals).

Technical terms

Chemoreceptor: Transmembrane or cytoplasmic protein that binds specific ligands to initiate chemotactic signalling.

Histidine kinase CheA: Central kinase that autophosphorylates in response to receptor signals and transfers phosphate to response regulators.

Response regulator CheY: Phosphorylated protein that interacts with the flagellar motor to control swimming behaviour.

Second messenger (c-di-GMP): Intracellular nucleotide that modulates diverse processes including motility and biofilm formation.

PAS domain: Per-Arnt-Sim structural module serving as an intracellular sensor for gases, light or redox signals.

Metagenome-assembled genome (MAG): Genomic reconstruction from environmental sequencing data, representing uncultured microbial populations.

References

1. d-amino acids signal a stress-dependent run-away response in Vibrio cholerae. Nature Microbiology (2023).
2. Ubiquitous purine sensor modulates diverse signal transduction pathways in bacteria. Nature Communications (2024).
3. MiST 4.0: a new release of the microbial signal transduction database, now with a metagenomic component. Nucleic Acids Research (2023).
4. Origin and functional diversification of PAS domain, a ubiquitous intracellular sensor. Science Advances (2023).
5. Accessing nutrients as the primary benefit arising from chemotaxis. Current Opinion in Microbiology (2023).