FIG 4.
sabA expression in H. pylori J99 and J99 sabA poly(T) mutants (nonthymine extensions). Quantitative real-time PCR was used to determine the relative expression of sabA in H. pylori J99 compared to that in mutants containing a poly(T) tract with various five-nucleotide insertions upstream and adjacent to the poly(T) tract. The data shown here are representative of the results obtained from three independent experiments, each conducted in technical triplicate. Error bars show standard errors of the means. Statistics were calculated using a Welch's unpaired t test of unequal variance with sabA poly(T)18 as the control (*, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001). Schematic representations of these mutants are shown in Fig. 1.