Fig. 9.

Single-molecule observations of transcription bursting. a A drawing depicting how multiple rounds of transcription on a circular template led to an accumulation of significant (+) torsional stress and inhibition of transcription in the presence of Topo I and absence of gyrase. The subsequent addition of gyrase recovered transcription. b Time dependence of T7 transcription initiation rate (blue) under the conditions shown in a. Transcription initiation was inhibited by (+) supercoiling, but then recovered after the addition of gyrase. Adapted from Chong et al. (2014) with permission