A new family of quorum sensing pheromones synthesized using S-adenosylmethionine and Acyl-CoAs.

It is now widely accepted that populations of bacterial cells often co-ordinate their behaviour via diffusible chemical signals. Many different signals have been documented, but they fall into a relatively small number of families. One such signal, CAI-1, from Vibrio cholerae consists of a substituted 13-carbon alkane. In this issue, Bassler and colleagues provide evidence that CAI-1 exemplifies an entirely new class of pheromones. They also show that one species of Vibrio synthesizes and detects just one such pheromone, while another species synthesizes and detects several. Bioinformatics and data from another group indicate that this new class of signals may be widespread among beta- and gamma-proteobacteria.