An artificial transcriptional activating region with unusual properties.

We describe a series of transcriptional activators generated by adding amino acids (eight in one case, six in another) to fragments of the yeast Saccharomyces cerevisiae activator Gal4 that dimerize and bind DNA. One of the novel activating regions identified by this procedure is unusual, compared with previously characterized yeast activating regions, in the following ways: it works more strongly than does Gal4's natural activating region as assayed in yeast; it is devoid of acidic residues; and several lines of evidence suggest that it sees targets in the yeast transcriptional machinery at least partially distinct from those seen by Gal4's activating region.