FIG. 7.

p130 acts during transcription complex assembly to inhibit Pol I transcription. Pol I and transcription factors were preincubated for 20 min at 30°C with buffer (lanes 3 and 5) or with 30 ng of GST-p130 (lanes 4 and 6); template DNA was added at the start (lanes 3 and 4) or end (lanes 5 and 6) of the preincubation. In lanes 7 and 8, the factors and Pol I were preincubated for 20 min at 30°C, together with template DNA, before GST-p130 (30 ng) was added (lane 8). Following preincubation, transcription was initiated by the addition of nucleotides. Lanes 1 and 2 show the transcription reactions without preincubation in the absence (lane 1) or presence (lane 2) of GST-p130 (30 ng).