Fig. 9.
FtsA induction by the ΔkhpA mutation is lost in the absence of an intact 5′-UTR leader of the ftsA transcript. A. Nucleotide (nt) sequence of 74 nt 5′-UTR leader of the ftsA transcript. The transcription start site, indicated in red, was determined by 5′-RACE (see Experimental procedures). The 49 nt deleted in the ftsA(ΔUTR) mutant are indicated in green. The retained 24 nt containing the RBS upstream of the start codon (ATG) are marked in purple. The same 24 nt was used as the RBS to express FtsA ectopically under control of the PZn promoter (Table S1). B. Representative Western blots of cellular amounts of FtsA, FtsZ, and MreC (control) in WT (IU1824) and ΔkhpA (IU9036), ftsA(ΔUTR) (IU13641), and ΔkhpA ftsA(ΔUTR) (IU13672) mutants growing exponentially in BHI broth. Numbers below lanes are luminescence values relative to WT, determined in the linear range of detection as described in Experimental procedures. C. Average (±SE) cellular amounts of FtsA, FtsZ, and MreC in mutants relative to WT from 3 independent experiments. P values were obtained relative to WT by one-way ANOVA analysis. * P<0.05; ** P<0.01; *** P<0.001; ns, not significantly different.