FIG. 3.

Primer extension analyses of transcripts originating from the opuC promoter. Cells were grown in BHI (OD ₆₀₀∼0.5), harvested, washed, and resuspended in 50 mM potassium phosphate buffer with 50 mM glucose (final concentration). NaCl was added to a final concentration of 3% to a portion of the cells, where appropriate. After a 20-min incubation, RNA was extracted, and 50 μg of each RNA sample was used as a template for extension of labeled CEX3 primer. Lanes: 1,10403S (WT); 2, 10403S plus 3% NaCl (WT+S); 3, LMA2B (sigB::Kan) (sigB); 4, LMA2B plus 3% NaCl (sigB+S). The sequence ladder was derived from reactions using the CEX3 primer, and the sequence shown to the right corresponds to the reverse complement. The nucleotide corresponding to the 3′ end of the extension product is underlined. The top strand sequence of the region immediately upstream of the transcription start site is shown at the bottom with the relevant + 1, −10, and −35 regions indicated.