FIG 1 .

Expression of LacY and LacZ under conditions of Ffh and/or 4.5S RNA or FtsY overexpression. E. coli cells harboring plasmid carrying arabinose-inducible ffh and/or ffs or ftsY were induced to overexpress the indicated proteins. (A) Growth was followed by measuring optical density at 600 nm, and representative semilog growth curves of the various transformants with and without IPTG induction are shown. (B) Expression of LacZ, LacY, Ffh, and FtsY was analyzed by Western blotting. The expression levels of LacZ and LacY were quantified and are shown as percentages of their expression levels in samples with empty vector. The experiments were repeated three times, and the results shown are representative, with standard deviations that did not exceed 10%. 4.5S RNA expression was analyzed by Northern blotting. As a loading control, antibodies against the ribosomal protein L15 were used.