Figure 6. In vitro transcription from several promoters by Eσ⁷⁰ and Eσ³⁸.

The figure shows scans of denaturing 5% polyacrylamide gels of transcriptions generated by RNA polymerase (E) with either Eσ³⁸ or Eσ⁷⁰, from supercoiled pSR plasmids carrying different promoters. As can be seen in all the gels, all the promoters were transcribed by both Eσ⁷⁰ and Eσ³⁸, with the exception of the poxB promoter which is not transcribed in vitro by σ⁷⁰. Different intensities indicate varying binding capacities. In all the gels the presence of a plasmid pSR correspondent RNA-I transcript produced with both sigmas, was detected, as previously reported [24]. The expression of this RNA-I was utilized as an internal control, since as expected in all the experiments was present. The sizes of the transcripts and the nucleotide sequences of the DNA fragments carrying these promoters corresponded to the expected for each promoter. Similar results were obtained in duplicate gels for several of the analyzed genes. (For details, see figure S2 and Materials and methods).