FIG. 4.

Transcriptional responses of the M. smegmatis wild-type strain and glnR deletion strain MH1 to nitrogen deprivation: hybridization of RNA isolated from M. smegmatis cells before and after induction of nitrogen starvation by incubation in nitrogen-free medium. (A) Transcription of the glutamine synthetase-encoding glnA gene, amtB and amt1 coding for ammonium uptake systems, and glnR in the wild type. The time points indicated (t₀, t₃₀, t₉₀, and t₁₅₀) are sampling times (in min) after resuspension of centrifuged and washed cells. One microgram of total RNA per spot was applied. (B) Transcription of genes in M. smegmatis glnR deletion strain MH1.