Fig. S4.

Dual control of ricI expression. (A) Salmonella ΔrprA cells carrying the ricI::gfp reporter and cotransformed with the indicated plasmids (Fig. 5B) were grown to early stationary phase and tested for RicI::GFP and σ^S production by Western blot. GroEL served as loading control. (B) Wild-type and ΔrprA cells carrying the translational ricI::lacZ reporter were cultivated to early stationary phase and tested for β-galactosidase production in the presence of bile salts or A22. (C) Western blot analyses of σ^S and RicI::3×FLAG production in ΔrprA cells (transformed with a low-copy plasmid carrying either the rprA, rprAC37, or rprAC63 allele) after A22 treatment. GroEL served as loading controls. (D) Analyses of σ^S, RicI::3×FLAG, and RprA production following activation and deactivation of the Rcs pathway using A22. Samples were collected at the indicated time points and probed for σ^S and RicI::3×FLAG (Western blot) as well as RprA (Northern blot) production. GroEL and 5S rRNA served as loading controls.