Fig. 5.

saeS^P transcripts are more stable than saeS^L transcripts. (A) Comparison of P3 promoter activities by lacZ reporter assays. NM, wild-type strain; Δ, sae deletion mutant NMΔsae; RS^P, NMΔsae(pCL-RS^P); PQRS^P, NMΔsae(pCL-PQRS^P); RS^L, NMΔsae(pCL-RS^L); PQRS^L, NMΔsae(pCL-PQRS^L). (B) Determination of saeS tran- script stability by real-time qRT-PCR. NMΔsae(pCL-RS^P) and NMΔsae(pCL-RS^L) were grown to exponential growth phase; then, transcription was blocked by rifampin. Cells were collected at the time points indicated, and total RNA was purified. The level of saeS transcripts was measured by real-time qRT-PCR. 16S rRNA was used as a control. Error bars represent standard deviations.