Fig. 4.

L. pneumophila tolC and lpw_07981 and their impact on surfactant and surface translocation. (A, top) Depiction of the region of the 130b chromosome containing genes lpw_07771, lpw_07761, and lpw_07751; i.e., the tolC operon. The horizontal gray arrows denote the size and orientation of the tolC operon, and the white arrows denote the two flanking genes. The vertical black arrowheads mark the locations of the insertion mutations in mutants NU390 and NU395. The thinner horizontal lines below the gene map signify the size and location of the two intergenic transcripts identified by RT-PCR. (A, bottom) Surface translocation and surfactant phenotypes of tolC mutants. WT 130b, tolC mutants NU390 and NU395, and complemented mutant NU390(pMtolC) were grown on BCYE plates containing 0.5% agar and 0.1 mM IPTG (isopropyl-β-d-thiogalactopyranoside) at 30°C for 7 days. (B, top) Depiction of the region of the 130b chromosome containing genes lpw_07991 and lpw_07981. The black arrowhead marks the locations of the insertions in lpw_07981 mutants NU402 and NU403. In the 130b database, the lpw_07981 ORF is also (erroneously) denoted lpw_07971. (B, bottom) Surface translocation and surfactant phenotypes of lpw_07981 mutants. WT 130b, lpw_07981 mutant NU402, and complemented mutant NU402(pMlpw_07981) were grown on BCYE plates containing 0.5% agar at 30°C for 7 days. The lpw_07981 mutant NU403 also consistently lacked surface translocation and surfactant (data not shown). The images presented in panels A and B are representative of those obtained from at least three independent experiments.