Fig. 3.

L. pneumophila bbcABCDEF and bbcGHIJK operons and their impact on surfactant and surface translocation. (A, top) Depiction of the region of the strain 130b chromosome containing genes lpw_24141 through lpw_24191, i.e., the bbcABCDEF operon. The horizontal gray arrows denote the relative size and orientation of the bbc genes, whereas the horizontal white arrows denote the two flanking genes. The vertical black arrowheads mark the approximate locations of the insertion mutations in mutants NU388, NU393, NU396, and NU397. The thinner horizontal lines below the gene map signify the approximate size and location of the four intergenic transcripts identified by RT-PCR analysis. (A, bottom) Surface translocation and surfactant phenotypes of bbcB and bbcF mutants. WT 130b, bbcB surfactant mutants NU388 and NU393, bbcF surfactant mutant NU396, and complemented mutant NU396(pMlpw24191) were grown on BCYE plates containing 0.5% agar at 30°C for 7 days. The bbcF mutant NU397 also consistently lacked surface translocation and surfactant (data not shown). (B, top) Depiction of the region of the strain 130b chromosome containing genes lpw_24131 through lpw_24091, i.e., the bbcGHIJK operon. The black arrowhead marks the location of the insertion in mutants NU389 and NU394, and the thinner horizontal lines signify the four intergenic transcripts identified by RT-PCR analysis. (B, bottom) Surface translocation and surfactant phenotypes of L. pneumophila bbcI mutants. WT 130b, bbcI surfactant mutants NU389 and NU394, and complemented mutant NU389(pMlpw_24111) were grown on BCYE plates containing 0.5% agar at 30°C for 7 days. The images of bacterial growth presented in panels A and B are representative of those obtained from at least three independent experiments.