Figure 5

Effects of S9 mutations in the brz and brb genes on bop transcription. In panel A, the upper blocks represent the 16S rRNA bands on the agarose gel stained by ethidium bromide. The lower blocks show northern blots of total cell RNA after probing with labeled DNA fragments containing the bop gene. Cells were grown in the dark and light. Culture OD₆₀₀ at which RNA was extracted is given at right. WT R1, wild-type strain R1; brz S9, strain brz S9; brb S9, strain brb S9; brz S9brb S9, strain brz S9brb S9. According to densitometry, the levels of bop mRNA (normalized to 16S rRNA) from strain brzS9 were: 59 ± 4% (OD₆₀₀ = 07.-0.8), not detectable (OD₆₀₀ = 1.1-1.2) of WT in the dark, and 65 ± 4% (OD₆₀₀ = 07.-0.8), 25 ± 1% (OD₆₀₀ = 1.1-1.2) in the light; from strain brbS9 they were: 88 ± 4% (OD₆₀₀ = 07.-0.8), 119 ± 6% (OD₆₀₀ = 1.1-1.2) of WT in the dark, and 135 ± 5% (OD₆₀₀ = 07.-0.8), 147 ± 6% (OD₆₀₀ = 1.1-1.2) in the light; and from strain brzS9brbS9 they were: 81 ± 5% (OD₆₀₀ = 07.-0.8), 83 ± 2% (OD₆₀₀ = 1.1-1.2) of WT in the dark, and 86 ± 5% (OD₆₀₀ = 07.-0.8), 115 ± 6% (OD₆₀₀ = 1.1-1.2) in the light. Panel B shows the locations of mutations in the brz and brb genes.