FIG. 4.

Transcription from double mutants in nonactivating and activating media. (A) Sequences of the mutants. The changed nucleotides in each of the double mutants are underlined. (B) Analysis of RNA from double mutants D1 and D2 in activating G-Gln medium. (C) Analysis of RNA from double mutants in nonactivating LB medium. The induced transcripts from the consensus M12 promoter in activating G-Gln medium are shown for comparison. (D) Analysis of RNA in a strain lacking (−) or containing (+) sigma 54 (rpoN).