Figure 4.
Comparison of transcriptional activity between RNA polymerase variants. (A) The RNA polymerase variants (64 nM) were reconstituted with saturating concentrations of σA (1:10). Holoenzymes were used to initiate transcription on three promoters as indicated. A representative image from three independent experiments is shown. (B) Transcription from the rrnB P1 promoter in dependence on increasing concentration of iNTP (GTP). The intensity of the transcripts generated by RNA polymerase containing RpoC-R88H was adjusted for better visibility. The relative activity of this mutant RNA polymerase was 2.5% of the wild type RNA polymerase at 2,000 μM GTP. Representative primary data are shown. The graph shows the averages of two replicates normalized for maximal transcription of each polymerase (set as 1).