FIG. 2.

Effects of TFE and TFE(C155A) addition on in vitro transcription. (A). Amounts of frh and hmtB transcripts synthesized after 30 min of incubation at 58°C in the presence of increasing amounts of TFE (listed in nanograms above the corresponding lanes in the gels shown), determined by ³²P-decay, plotted as percentages of the maximum amount of that transcript synthesized. (B) Run off transcripts synthesized from the promoter listed above each gel (28, 29) in reaction mixtures with no addition (−) or supplemented with 200 ng of TFE (+) or with 200 ng of TFE(C155A) (CA). The amount of each transcript synthesized was determined by ³²P-decay measurements, and the length of each transcript (130 to 260 nucleotides) was confirmed, based on the location of the corresponding TATA box, by adjacent coelectrophoresis of ³²P-labeled size standards (Boehringer-Mannheim, Indianapolis, Id.). Below the lanes are mean values, from three to seven independent experiments, of the amount of transcript synthesized in the presence of TFE (+) or TFE(C155A) (CA) relative to the amount synthesized with no addition (−).