FIG. 2.

(A and B) RT-PCRs to compare levels of transcripts for genes whose products show homology to histidine kinase (HK), a protein of unknown function (gene C), and a PBP in strains LO28 (L) and LO28ΔlisK (ΔK) (A) and LO28ΔlisK(pNZ44lisR) (+R) and LO28ΔlisK(pNZ44) (−R) (B). (C) Confirmation of the overexpression of lisR by RT-PCR using lisR-specific PCR primers to amplify cDNA templates of equal concentrations generated from LO28ΔlisKNICE(pNZ8048) or LO28ΔlisKNICE(pNZ8048-lisR) RNA following nisin induction. In all cases control PCR primers were used to ensure the complete removal of DNA from RNA preparations prior to reverse transcription and to ensure that levels of cDNA for samples that were to be compared were equal.