Improvement of yeast tolerance to acetic acid through Haa1 transcription factor engineering: towards the underlying mechanisms.

Our data confirms that engineering of the regulon-specific transcription factor Haa1 allows the improvement of acetic acid tolerance in S. cerevisiae. It was also shown that the beneficial S135F mutation identified in the current work did not lead to an increase of HAA1 transcript level, suggesting that an altered protein structure of the Haa1S135F mutant protein led to an increased recruitment of the transcription machinery to Haa1 target genes.