Figure 3.

The effects of ppGpp and DksA on pR promoter half-life. (A) The time course of competitor-resistant open complexes was monitored by in vitro transcription challenged by heparin in the presence of none addition (DksA storage buffer, open squares), ppGpp at 200 μM (closed squares), DksA at 400 nM (triangles) or DksA at 400 nM with addition of 200 μM ppGpp (circles). The values found at 20 s after competitor addition were set as 1. Data are the average from three independent experiments with standard errors. (B) The autoradiogram from the experiment performed as shown in the (A).