Characterization of the czr and ncz promoter regions. (A) Beta-galactosidase activity assay of transcription fusions of Pczr and Pncz to the lacZ reporter gene. Cells were grown in PYE medium and samples were taken at midlog phase and stationary phase (24 h) for assaying β-galactosidase as described . The background activity for plasmid alone is around 200 Miller Units. Asterisks indicate results significantly different between the two growth phases within each promoter fusion (p ≤ 0.05). (B) Determination of co-transcription of CCNA02805 and CCNA_02806 by amplification with primers RND3 and RND4. Lane 1, PCR amplification using cDNA previously synthesized with Reverse Transcriptase from total RNA from the NA1000 strain; lane 2, PCR amplification from total NA1000 genomic DNA (positive control); lane 3, PCR amplification from total RNA from the NA1000 strain (negative control). The 0.43 kb fragment corresponding to the amplified products is indicated.