FIG 1.

A quorum sensing system in the Teredinibacter sp. strain 2052S genome is adjacent to a conserved biosynthetic gene cluster. (A) Quorum sensing genes (tbaI and tbaR) neighbor a predicted hybrid trans-AT-PKS-NRPS biosynthetic gene cluster (3). Identified putative TbaR-binding sites are represented by dotted lines from their position in the cluster and list the number of base pairs they are located upstream of the start codon of the indicated gene. Numbers correspond to locus tags (K256DRAFT_XXXX) in the Joint Genome Institute Integrated Microbial Genomes (IMG) system (25). Genes are colored according to predicted function in antiSMASH 6.0 (26). (B) Comparison of known LuxR-type binding sites in the promoter sequences of Aliivibrio fischeri luxI, Ralstonia solanacearum solI, and Methylobacter tundripaludum mbaI with the putative TbaR-binding sites upstream of the acyl-HSL synthase gene tbaI and predicted PKS gene K256DRAFT_2890. (C) Response of E. coli reporter strains containing gfp fused to different promoter regions with putative TbaR-binding sites shown in B to 100 nM C₁₀-HSL or ethyl acetate (vehicle). Data are the mean ± standard deviation of three technical replicates and are representative of two independent experiments. RFU, relative fluorescence units; OD, optical density.