Fig. 2.

The SgrS antisense domain is required for SopD repression. (A) Northern blot analysis of WT and sgrS mutant Salmonella challenged with the glucose analog αMG. Samples were withdrawn before and at the indicated time points posttreatment. Total RNA isolates were inspected for sopD and SgrS expression using gene-specific probes; 5S rRNA served as a loading control. (B) Western blot analysis of SopD::3×FLAG protein in WT and ΔsgrS strains at various conditions of Salmonella growth (OD₆₀₀ of 0.5, 1.0, 2.0, 3, and 6 h after cells had reached OD₆₀₀ = 2.0 as well as SPI-1–inducing conditions). GroEL served as an internal loading control. (C) Western blot analysis of SopD::3×FLAG protein in WT, ΔsgrS, Δhfq, or ΔsgrS/Δhfq bacteria. Strains were transformed with the indicated plasmids and grown under SPI-1–inducing conditions. Total protein was extracted, and SopD::3×FLAG proteins levels were inspected by Western blot.