FIG. 2.
In vitro transcription of promoters containing or lacking native upstream sequences. (A) rrnD P1 promoters with upstream endpoints of −60 or −41 (plasmid templates pRLG3266 and pRLG3267) transcribed with 0.5 nM wild-type (WT) RNAP (lanes 1 to 4) or 0.5 nM αR265A mutant RNAP (lanes 5 to 8). (B) λ pR promoters with upstream endpoints of −61 or −42 (plasmid templates pRLG2229 and pRLG936) transcribed with 1 nM wild-type RNAP. (C) RNA II promoters with upstream endpoints of −150 or −42 (plasmid templates pRLG934 and pRLG938) transcribed with 2 nM wild-type RNAP. In each experiment, transcripts were separated on a 5% acrylamide–7 M urea gel, and the promoter-specific and the vector-encoded RNA I transcripts are indicated.