Figure 5.

Effect of Rsd on in vitro transcription. A fixed amount of σ⁷⁰ (1 pmol) and increasing amounts of Rsd (lanes 2–5, 1, 2, 5, and 10 pmol) were preincubated for 10 min at 30°C in our standard transcription mixture containing 50 mM NaCl (24), and then 1 pmol of core enzyme was added. After 10 min at 37°C, a DNA fragment (1 pmol) carrying the indicated promoter was added, and the mixture was incubated at 37°C for 30 min to allow the open complex formation. RNA synthesis was initiated by adding a substrate/heparin mixture and continued for 5 min at 37°C. Transcripts were analyzed by electrophoresis on 6% or 8% polyacrylamide gels containing 8 M urea.