Figure 2.

Mutating the nontranscribed strand U6 promoter. (A) Changes of the TATA box and T₇-stretch (boxed) are highlighted in bold letters. Percent transcriptional activity with TFIIIB only (i.e., no TFIIIC) relative to the respective wild-type reference (wt; set to 1.0) is shown at the right (the numbers represent averages ± SEM of at least five independent experiments). (B) Transcription assay. The effects of mutations were assessed for transcription of duplex DNA (lanes 1–8) and the −6 o/h template (lanes 9–16) in the presence of TFIIIB only (Upper) or TFIIIB and TFIIIC (Lower).