Figure 2. Effect of FtsY-depletion on the stability of MdfA-PhoA and on the amount of its coding mRNA.
E. coli FJP10 harboring plasmid pT7-5/MdfA-PhoA was grown with and without arabinose in 2YT broth for 4.5 h and transferred into M9 minimal broth for [35S]-methionine labeling. (A) Samples taken at the indicated time points after the chase with cold methionine were analyzed by immunoprecipitation using anti-alkaline phosphatase antibodies. (B) The amount of labeled MdfA-PhoA was quantified by densitometry and the average of three independent assays is shown, with error bars representing standard deviations. (C) The expression levels of MdfA-PhoA mRNA were analyzed using real time PCR and normalized to that of ribosomal 16S rRNA. Samples without arabinose (-FtsY and –Ffh) were set to 100%. The average of three separate assays is shown, with error bars representing standard deviations.