Fig. 4

Northern blot analysis of iolX transcription in strains of B. subtilis. RNA samples were prepared from strains 168 (lanes 1–3), CM101 (ΔyisR) (lanes 4–6), and CM102 (ΔiolQ) (lanes 7–9), which were grown in S6 medium containing 0.5% casamino acid and 0.005% tryptophan alone (lanes 1, 4, and 7) and in the same medium supplemented with 10 mM MI (lanes 2, 5, and 8) or 10 mM SI (lanes 3, 6, and 9). The arrowhead indicates the iolX transcripts. The lower panel shows ribosomal RNA (16S and 23S) as the loading control