FIG. 3.

Recombinant MOT1 can activate or repress basal transcription driven by the HIS4 core promoter. (A) Experiments were performed as described in the legend to Fig. 2, but with increasing amounts of baculovirus-expressed MOT1 (rMOT1). Transcription reactions were performed in standard potassium glutamate-containing buffer (lanes 1 to 7) or in buffer containing potassium acetate (lanes 8 to 14) (see Materials and Methods). The reaction mixtures contained 10 ng (lanes 2 and 9), 50 ng (lanes 3 and 10), 100 ng (lanes 4 and 11), 300 ng (lanes 5 and 12), 600 ng (lanes 6 and 13), or 1,000 ng (lanes 7 and 14) of MOT1. The bands that were quantitated are indicated by the arrow. (B) Quantitation by phosphorimager analysis of the data shown in panel A. The graph on the left is of data from lanes 1 to 7, and the graph on the right is of data obtained from lanes 8 to 14. For comparison with the results obtained with purified MOT1 from yeast (yMOT1), the x axes also indicate the approximate units of MOT1 activity added.