FIG. 3.

Correction of the ΔRPB4 in vitro transcription defect by the Sro9p, Nsp1p, and RPB7 suppressors. (A) Some GST-fused suppressor proteins can ameliorate the ΔRPB4 transcription defect in vitro. Twenty and 50 ng of recombinant GST fusion proteins were added as indicated to in vitro transcription reactions using ΔRPB4 whole-cell extracts. Consistent results were obtained in three independent experiments. (B) GST fusion proteins have no stimulating effect on in vitro transcription with wild-type extracts. Fifty nanograms of the respective recombinant proteins used in panel A was added to transcription reactions as indicated. (C) Whole-cell extracts were prepared from the strains indicated and were used in the same in vitro transcription assay used in panels A and B. Consistent results were obtained in three independent experiments.