FIGURE 2.

Expression of VapC-mt4 leads to translational arrest and RNA cleavage. A, [³⁵S]methionine incorporation into E. coli BW25113Δ6 cells with or without VapC-mt4 expression. Equivalent amounts of cell lysate were subjected to SDS-PAGE followed by autoradiography. Numbers indicate the time (min) after VapC-mt4 induction. Data shown are representative of three independent experiments. B, quantification of [³⁵S]methionine incorporation into E. coli BW25113Δ6 cells with (●) or without (□) VapC-mt4 expression. Data points represent the average of three independent experiments; error bars represent the S.D. Time points correspond to those in A. C, Northern analysis for tufA, ompA, and lpp mRNAs extracted from E. coli BW25113Δ6 cells with or without expression of VapC-mt4. VapC-mt4 expression results in a gradual decrease in the steady-state levels of tufA, ompA, and lpp mRNAs. Numbers above lanes indicate the time (min) after VapC-mt4 induction. Numbers below lanes indicate the band intensity relative to the zero time point.