Transcriptional Regulation of the rsbV Promoter Controlling Stress Responses to Ethanol, Carbon Limitation, and Phosphorous Limitation in Bacillus subtilis
Figure 2
Effects of various mutations and conditions on the ethanol stress response of the σ B-dependent rsbV promoter with cells growing exponentially in LB medium. (a) At time = 0, ethanol was added to a final volume of 4%, giving rise to a 4-5-fold enhancement of promoter activity in the wild-type genetic background (rsbV1) (■). The mutations (Figure 1) decreased the basal as well as the induced activities of the promoter. Wild type (■); ccpA mutant (); hprK mutant (); the rsbV1m1 mutant (◆); rsbV3 (lacking the TnrA binding site) (▾) rsbV5 (lacking the TnrA and CcpA binding sites) (▴). (b) Effects of the loss of CcpA (), TnrA (▴), or both transcription factors (◆) on the ethanol stress response of the σ B-dependent promoter in the rsb operon. (c) Effect of glucose on the ethanol stress response of the rsbV promoter. The experiment was conducted in LB medium with (closed symbols) and without (open symbols) 1% glucose. The wild type (squares) and ccpA mutant (circles) were examined. (d) Response of the σ B-dependent ctc gene to ethanol stress. A lacZ fusion was made to the ctc gene, and the response to 4% ethanol was measured in the wild-type background (■), the ccpA mutant background (), the rsbV1m1 genetic background (◆), and the rsbV5 genetic background (▴). The experiment was conducted in LB medium under standard conditions. Ethanol (4%) was added at .
); hprK mutant (); the rsbV1m1 mutant (◆); rsbV3 (lacking the TnrA binding site) (
