FIG 1.

A quorum sensing system in Methylobacter tundripaludum. (A) The quorum sensing genes in Methylobacter tundripaludum flank a predicted nonribosomal peptide synthetase (NRPS) biosynthetic gene cluster. The arrows and asterisks identify putative MbaR-binding sites shown in Fig. 1B. The numbers below gene arrows are locus tags (T451DRAFT_0XXX) corresponding to the Joint Genome Institute Integrated Microbial Genomes (IMG) system (41). Due to space constraints, locus tags for transposase/integrase genes (white) have been omitted. Genes are colored as follows according to predicted function: luxI family AHL synthase gene mbaI, blue; luxR family transcription factor gene mbaR, green; antiSMASH-classified core NRPS genes, red (from left to right, acyl carrier protein, condensation domain, adenylation domain, and esterase genes); other biosynthetic genes, orange; efflux pump genes, yellow; transposase/integrase genes, white; mbaI' pseudogene, purple; and other genes, gray. (B) Comparison of putative MbaR-binding sites in front of the AHL synthase gene mbaI and the pseudogene mbaI' with known LuxR-type binding sites in the promoter sequences of Vibrio fischeri luxI, Pseudomonas aeruginosa rhlI, and Ralstonia solanacearum solI.