An artificial transcriptional activating region with unusual properties

We describe a series of transcriptional activators generated by adding amin o acids (eight in one case, six in another) to fragments of the yeast Sacch aromyces cerevisiae activator Gal4 that dimerize and bind DNA. One of the n avel activating regions identified by this procedure is unusual, compared w ith previously characterized yeast activating regions, in the following way s: it works more strongly than does Gal4's natural activating region as ass ayed in yeast; it is devoid of acidic residues; and several lines of eviden ce suggest that it sees targets in the yeast transcriptional machinery at l east partially distinct from those seen by Gal4's activating region.