Ngg1 transcription regulator. Could inhibit GAL4 DNA-binding or its ability to activate transcription. Functions as component of the transcription regulatory histone acetylation (HAT) complexes SAGA SALSA SLIK and ADA. SAGA is involved in RNA polymerase II-dependent transcriptional regulation of approximately 10% of yeast genes. 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 (SPT3 SPT8 and SPT20) and promoter selectivity interaction with transcription activators (GCN5 ADA2 ADA3 and TRA1) 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 at least after activation at the GAL1-10 locus. ADA preferentially acetylates nucleosomal histones H3 (at Lys-14 and Lys-18) and H2B.
NGG1 consists of 702 amino acids with molecular mass of 79282 Da