FIG. 3.

Overexpression of TBP stimulates rRNA transcription in a strain with an inactive UAF (ΔRRN5). Newly made rRNAs in various strains were pulse-labeled and separated by gel electrophoresis, and the radioactive bands were detected by fluorography. The positions of mature 18S and 25S rRNAs are indicated. TBP overexpression has no effect on rRNA synthesis in a wild-type (wt) strain (RLY01, compare lanes 1 and 2). In contrast, TBP overexpression in a ΔRRN5 strain stimulates rRNA synthesis (RLY07) (lanes 3 and 4). As expected, no rRNA synthesis is detected in a ΔRRN11 strain, with or without TBP overexpression (RLY02) (lanes 5 and 6).