FIG. 4.
Determination of the t1/2s of the pdxA-ksgA cotranscript and ksgA- and pdxB-specific transcripts of E. coli K-12 growing exponentially in LB-Glc. Equal amounts of RNA isolated from NU426 growing in LB-Glc before (lane 1) and at various times after (lanes 2 to 5) rifampin addition were probed as described in Materials and Methods. Positions of bands corresponding to the pdxA-ksgA cotranscript and the ksgA- and pdxB-specific transcripts are indicated. Analogous experiments were performed for NU426 grown at additional growth rates (data not shown; Results). Lane 6, amounts of the same transcripts from NU426 subjected to starvation for amino acids (Results). The results shown are from at least three independent cultures at each growth rate.