Fzf1p of Saccharomyces cerevisiae is a positive regulator of SSU1 transcription and its first zinc finger region is required for DNA binding

The FZF1 gene of Saccharomyces cerevisiae encodes a five-zinc-finger transc ription factor involved in sulphite tolerance. Previous work based on multi copy suppression analysis placed FZF1 upstream of SSU1, which encodes a pla sma membrane protein and putative transporter also implicated in sulphite d etoxification. Consistent with this analysis, Fzf1p was found to be a posit ive regulator of SSU1 transcription. The SSU1 promoter region involved in a ctivation by FZF1 was defined, and the Fzf1 protein was shown to bind to it directly in vitro. Deletion of a single, amino-terminal zinc finger of Fzf 1p resulted in loss of DNA binding, while the fourth and fifth zinc fingers were found to be dispensable. Copyright (C) 1999 John Wiley & Sons, Ltd.