FIGURE 5.

Protein secretion profile in the presence of a dominant negative H-NS mutant. (A) Secreted proteins from WT enteropathogenic Escherichia coli (EPEC) and its Δler, ΔgrlR, Δhns, ΔgrlA, ΔgrlRA, ΔgrlRΔler, ΔlerΔgrlA, ΔlerΔgrlRA, and ΔescN derivative mutants, carrying plasmid pT6-HNS/G113D expressing H-NS^G113D, grown in 50 ml Lysogeny Broth (LB) with (+) and without (–) 0.1% arabinose at 37°C with shaking, were concentrated from culture supernatants by precipitation with trichloroacetic acid (TCA), separated by 12% SDS-PAGE and stained with Coomassie brilliant blue. (B) Total extracts were prepared from the corresponding bacterial pellets and separated by 12% SDS-PAGE. Tir and EscJ expression was analyzed by western blotting using an anti-Tir monoclonal antibody and anti-EscJ polyclonal antibodies. As a control for protein loading, GroEL expression was also analyzed using an anti-GroEL monoclonal antibody.