YEAST GAL11 PROTEIN STIMULATES BASAL TRANSCRIPTION IN A GENE-SPECIFIC MANNER BY A MECHANISM DISTINCT FROM THAT BY DNA-BOUND ACTIVATORS

The GAL11 gene encodes an auxiliary transcription factor required for full expression of many, if not all, genes of the yeast Saccharomyces cerevisiae. We have recently shown that GAL11-encoded protein (Gal11p) enhances basal transcription from the CYC1 promoter in a cell-free transcription system [(1993) Proc. Nail. Acad. Sci. USA 90, 8382-8386]. Here we indicate that Gal11p stimulates basal transcription in a gene-specific manner in vitro. We further suggest that the mechanism underlying the transcriptional stimulation by Gal11p is distinct from that by DNA-bound activators, since Gal11p stimulated transcription in a reaction system where activators were unable to enhance transcription due to the lack of intermediary factors.