Functions as component of the transcription regulatory histone acetylation (HAT) complexes SAGA, SALSA and ADA. SAGA is involved in RNA polymerase II-dependent transcriptional regulation. At the promoters, SAGA is required for recruitment of the basal transcription machinery. It influences RNA polymerase II transcriptional activity through different activities such as TBP interaction and promoter selectivity, interaction with transcription activators, and chromatin modification through histone acetylation (gcn5) and deubiquitination (ubp8). SAGA acetylates nucleosomal histone H3 to some extent (to form H3K9ac, H3K14ac, H3K18ac and H3K23ac). SAGA interacts with DNA via upstream activating sequences (UASs). SALSA, an altered form of SAGA, may be involved in positive transcriptional regulation. SLIK is proposed to have partly overlapping functions with SAGA. It preferentially acetylates methylated histone H3. ADA preferentially acetylates nucleosomal histones H3 (to form H3K14ac and H3K18ac) and H2B (By similarity). Required for full activation of chromatin alteration and meiotic recombination at meiotic recombination hot spot ade6-M26. Also required for the regulation of transcription and chromatin structure around ade6-M26 in response to osmotic stress. Needed for hyperacetylation of histone H3 around ade6-M26. Component of the SAGA, SALSA, SLIK and ADA complexes. Cells are sensitive to replication stress hydroxyurea (HU) and also exhibits weak sensitivity to ultraviolet (UV) and methylmethane sulfonate (MMS).