6cw2

Structural highlights

Function

[GCN5_YEAST] Acetylates histone H2B to form H2BK11ac and H2BK16ac, histone H3 to form H3K9ac, H3K14ac, H3K18ac, H3K23ac, H3K27ac and H3K36ac, with a lower preference histone H4 to form H4K8ac and H4K16ac, and contributes to H2A.Z acetylation. Acetylation of histones gives a specific tag for epigenetic transcription activation. Operates in concert with certain DNA-binding transcriptional activators such as GCN4 or HAP2/3/4. Its acetyltransferase activity seems to be dependent on the association in different multisubunit complexes. Functions as histone acetyltransferase component of the transcription regulatory histone acetylation (HAT) complexes SAGA, SALSA 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. The ADA histone acetyltransferase complex preferentially acetylates nucleosomal histones H3 (to form H3K14ac and H3K18ac) and H2B, leading to transcription 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.^{[1] [2] [3]}

See Also

• Antibody 3D structures
• Histone acetyltransferase 3D structures

References

1. ↑ Grant PA, Eberharter A, John S, Cook RG, Turner BM, Workman JL. Expanded lysine acetylation specificity of Gcn5 in native complexes. J Biol Chem. 1999 Feb 26;274(9):5895-900. PMID:10026213
2. ↑ Babiarz JE, Halley JE, Rine J. Telomeric heterochromatin boundaries require NuA4-dependent acetylation of histone variant H2A.Z in Saccharomyces cerevisiae. Genes Dev. 2006 Mar 15;20(6):700-10. PMID:16543222 doi:http://dx.doi.org/10.1101/gad.1386306
3. ↑ Millar CB, Xu F, Zhang K, Grunstein M. Acetylation of H2AZ Lys 14 is associated with genome-wide gene activity in yeast. Genes Dev. 2006 Mar 15;20(6):711-22. PMID:16543223 doi:http://dx.doi.org/20/6/711
4. ↑ Sun J, Paduch M, Kim SA, Kramer RM, Barrios AF, Lu V, Luke J, Usatyuk S, Kossiakoff AA, Tan S. Structural basis for activation of SAGA histone acetyltransferase Gcn5 by partner subunit Ada2. Proc Natl Acad Sci U S A. 2018 Sep 17. pii: 1805343115. doi:, 10.1073/pnas.1805343115. PMID:30224453 doi:http://dx.doi.org/10.1073/pnas.1805343115