Figure 4.
The average transcription elongation rate varies non-monotonically with kon for different values of σbasal. Here, σbasal is the overall supercoiling density in the genomic segment in the absence of any transcription. At low kon, the average RNAP velocity is higher for |σbasal| > 0. This effect disappears in the RNAP collective behavior regime. Finally, at very high values of kon, the average RNAP velocity is higher if the genomic DNA is maintained in a state with positive basal supercoiling density.