FIG 6.

Deletion of rpoE reduces transcription of csrB and csrC. (A) Nucleotide sequences of the csrB and csrC promoter regions. Promoter −35 and −10 elements, as well as the transcription start sites (+1), are shown. (B and C) Primer extension analysis of csrB (B) and csrC (C) of total cellular RNA extracted from stationary-phase cultures. Lane 1, WT; lane 2, ΔhicB mutant; lane 3, ΔhicB ΔrpoE mutant; lane 4, ΔrseA mutant. Transcription start sites (+1) are marked. (D) β-Galactosidase activity (units of milligram of protein) ± standard deviation of csrB-lacZ and csrC-lacZ transcriptional fusions was determined during stationary phase in WT (black) and ΔhicB (red), ΔhicB ΔrpoE (gray), and ΔrseA (blue) mutant strains. Experiments were performed three times.