Figure 2. mreB is essential in L. pneumophila.

(A) Schematic representation of the inducible allele of mreB. A synthetic DNA sequence carrying the gentamicin resistance gene aacC1, the lacIq gene (large black arrows) and a synthetic promoter with two LacO sites (black arrow and black dots) was inserted between the comEA gene and the mreBCD locus (large grey arrows). (B) Plating of ten-fold serial dilutions of the lpp0148_TAA mreB^ind strain on CYE plates containing different amount of IPTG. (C) Growth curve of the lpp0148_TAA mreB^ind strain in AYE in the presence of various concentration of IPTG. The culture was initiated with the lpp0148_TAA mreB^ind strain previously grown on a CYE plate with 20 μM of IPTG and resuspended in warm medium (starting OD₆₀₀ = 0.1). Absorbance of the culture was monitored at 600 nm every 15 min with intermittent shaking in a 96-well plate reader.