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 transcription factor involved in sulphite tolerance. Previous work based on multicopy suppression analysis placed FZF1 upstream of SSU1, which encodes a plasma membrane protein and putative transporter also implicated in sulphite detoxification. Consistent with this analysis, Fzf1p was found to be a positive regulator of SSU1 transcription. The SSU1 promoter region involved in activation 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 Fzf1p resulted in loss of DNA binding, while the fourth and fifth zinc fingers were found to be dispensable.