FIG. 6.

legA and cegC genes are regulated by the CpxR regulator. (A) Sequence alignment of the regulatory regions of the legA and cegC genes (legA10, legA11, cegC1, cegC2, cegC3, and cegC4). The putative consensus sequence is indicated by boldface type, and the distances to the first ATG codon are also indicated. The complementary strand is shown for genes (legA10, cegC1, and cegC2) in which the consensus regulatory element was identified on the reverse strand. (B) Expression of the four cegC genes and the two legA genes in L. pneumophila wild-type strain (dark grey bars) and cpxR mutant strain OG2002 (open bars). For the cegC genes lacZ fusions containing a mutation in the CpxR consensus sequence were also examined in the L. pneumophila wild-type strain (light grey bars). β-Galactosidase activity was determined as described in Materials and Methods. The data are the averages ± standard deviations (error bars) of at least three different experiments. MU, Miller units.