FIG 4.
Relative contributions of the pause hairpin and T tract/U tract for pausing. (A) Sequence comparison of the 107 and 144 pause hairpins, RNA U tracts, and ntDNA T tracts. (B to E) Single-round in vitro transcription reactions were performed with various DNA templates in the absence or presence of 1 μM NusA and/or 1 μM NusG, as indicated. Reactions were stopped at the times shown above the lanes. Chase reactions (Ch) were extended for an additional 10 min at 37°C in the presence of 500 μM (each) NTPs. The position of the U107 pause transcript is marked. Pause half-life (t1/2) values and standard deviations are shown at the bottom of each set of lanes. Each experiment was performed at least twice and representative gels are shown.