FIG 4.
Expression of cwlO sense and antisense transcripts. (A) Schematic diagram of the nucleotide sequence at the 3′ end of the cwlO operon. The cwlO terminator is shown by inverted arrows followed by carets located downstream of the open reading frame. The location of the cwlO sense transcript is indicated by a full arrow. The SigB promoter motifs are underlined. The initiation point of transcription of the antisense transcript is indicated by +1 and its length by a broken line. (B) Detection of the cwlO antisense RNA by Northern blotting. Transcription of the heterogeneous antisense transcript begins in wild-type cells (WT) growing in LPDM at the onset of phosphate limitation (T0), and the transcript persists for up to 3 h (T3). The transcript is not detected in phosphate-limited cells of strain LS047 (ΔPsigB), which has the SigB promoter deleted. RNA size markers are shown on the left.