FIG. 2.

Derepression of S. enterica serovar Typhi ompS1 in an hns background. Bars indicate the specific β-galactosidase activity. (A) Expression in the S. enterica serovar Typhi wild-type strain and in the isogenic hns99 derivative. Complementation was with cloned S. enterica serovar Typhi wild-type hns or with the pACYC184ΔTc vector. (B) Expression from reporter fusions of different lengths in the S. enterica serovar Typhi wild-type strain and in the hns99 derivative. Numbers indicate the length of the ompS1 regulatory region fused to lacZ, as depicted in Fig. 1. Results are the averages and standard deviations from three independent experiments. An absence of error bars indicates that the standard deviation was too small to be shown.