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Irazoki O, Ter Beek J, Alvarez L, Mateus A, Colin R, Typas A, Savitski MM, Sourjik V, Berntsson RP, Cava F
Nat. Microbiol 8 (8) 1549-1560 [2023-08-00; online 2023-06-26]
To explore favourable niches while avoiding threats, many bacteria use a chemotaxis navigation system. Despite decades of studies on chemotaxis, most signals and sensory proteins are still unknown. Many bacterial species release D-amino acids to the environment; however, their function remains largely unrecognized. Here we reveal that D-arginine and D-lysine are chemotactic repellent signals for the cholera pathogen Vibrio cholerae. These D-amino acids are sensed by a single chemoreceptor MCPDRK co-transcribed with the racemase enzyme that synthesizes them under the control of the stress-response sigma factor RpoS. Structural characterization of this chemoreceptor bound to either D-arginine or D-lysine allowed us to pinpoint the residues defining its specificity. Interestingly, the specificity for these D-amino acids appears to be restricted to those MCPDRK orthologues transcriptionally linked to the racemase. Our results suggest that D-amino acids can shape the biodiversity and structure of complex microbial communities under adverse conditions.
PubMed 37365341
DOI 10.1038/s41564-023-01419-6
Crossref 10.1038/s41564-023-01419-6
pmc: PMC10390336
pii: 10.1038/s41564-023-01419-6