Fig. 1.

Identification of NGR234 AHL-degrading cosmid clones. Partial physical maps of the identified cosmid clones pWEB-TNC-B2, -C6, -A5, -B9, and -G2 carrying the putative genes dlhR, qsdR1, hitR-hydR, qsdR2, and aldR are shown. Cosmid clones pWEB-TNC-B2 and -C6 were mapped on pNGR234b, whereas cosmids pWEB-TNC-A5, -B9, and -G2 were located on the bacterial chromosome. Black arrows indicate the ORFs that were involved in QQ. Gray-shaded arrows indicate flanking ORFs that were not linked to the QQ phenotypes. ORFs are designated using ORF identification numbers from GenBank entries CP000874 and CP001389 (prefix NGR_∼). The scale bar represents 1 kb. A possible secretion signal (SP) in dlhR is indicated by an inverse open triangle. Positions of in vitro transposon insertions in the identified QQ genes are indicated by filled and inverse triangles.