FIG. 1.

Deletion of hha increases SseB protein levels. Bacterial cultures (wild type [wt] and ΔydgT, ΔhhaT, and ΔydgT Δhha mutants) were grown under SPI-2-inducing conditions in LPM (pH 5.8) (A) and under SPI-2-repressing conditions in LB broth (B) as described in the text. Bacterial cell lysates were probed by Western blot analysis for the SPI-2-encoded protein, SseB (top panels), and a control protein (intracellular DnaK) (bottom panels). (C) Complementation of hha deletion. Wild-type Salmonella serovar Typhimurium and the Δhha mutant were transformed with phha, carrying the full-length wild-type hha strain from an IPTG-inducible promoter. Strains were grown in LB and probed by Western blot analysis for SseB as described in the text. The data shown are representative of experiments performed three times.