Fig 3.

Effects of δ on the open complex of rrnBp₁ and Pveg. (A) Primary data showing the effect of delta on open-complex stability at rrnBp₁ and Pveg (LK7 and LK1). Open complexes were formed with E or E+δ, and at time zero heparin was added. Heparin binds to free RNAP but not to RNAP in complex with DNA. At indicated time intervals, aliquots were withdrawn and transcription was initiated with all four NTPs. The amount of the transcript reflected the amount of the open complex. (B) Representative graph for rrnBp₁ open complex decay experiments. The half-life of its open complex was 33 ± 7 s with E (open circles) and 10 ± 2 s with E+δ (filled circles). These numbers are averages and standard deviations (SDs) calculated from three independent experiments. (C) Representative graph for Pveg open-complex decay experiments. The half-life of its open complex was 33 ± 2 min with E (open circles) and 8 ± 2 min with E+δ (filled circles). These numbers are averages, and SDs were calculated from three independent experiments.