Transcriptional Regulation of the rsbV Promoter Controlling Stress Responses to Ethanol, Carbon Limitation, and Phosphorous Limitation in Bacillus subtilis
Figure 1
Schematic depiction of the rsb or sigB operon in B. subtilis (top) as well as the constructs made in order to determine the involvement of putative CcpA and TnrA binding sites in control of σ B promoter activity in response to various stresses. The octacistronic operon as well as the two promoters, one dependent on σ A-RNA polymerase in front of the rsbR gene and one dependent on σ B-RNA polymerase in front of the rsbV gene, are shown. The wild-type control region (nucleotides to ) including the putative TnrA binding site (open arrow), the putative CcpA binding site (closed arrow), and the σ B promoter was fused to the lacZ gene encoding β-galactosidase as the reporter gene. The wild-type construct is designated by rsbV1. In the second construct, rsbV1m1, the CcpA binding site (CRE) was mutated, changing the central conserved C to an A (see sequence on right-hand side of the construct). In the rsbV3 construct, the control region started at position 238, and the TnrA binding site (TRE) was thereby deleted. In construct rsbV5, the control region started at position 215, and consequently the CRE site as well as the TnrA binding site was thereby deleted. All constructs were inserted in the chromosome at the amyE locus.
