Figure 4.

Transcription activity of gapped promoters. (A) Gapped promoter templates. The upstream edge of the single-stranded gap is indicated by a solid arrow for each construct; open arrows indicate the downstream edge of the gap for the −12 o/h and −6 o/h series, respectively. (B) Transcription with gapped promoter templates. TFIIIB-dependent transcription was carried out with the gapped promoters (lanes 3–8 and 10–15) and with duplex DNA and −12 o/h and −6 o/h constructs (lanes 1, 2, and 9, respectively) as controls/references. The nomenclature follows A: e.g., −35/−6 is the construct with a transcribed strand gap extending from nucleotide −34 to nucleotide −7. (The transcription start site of the active −6 gap constructs is at base pair −2; the start site for the active −12 gap constructs is at base pair −8.)