1e6i
From Proteopedia
Bromodomain from GCN5 complexed with acetylated H4 peptide
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] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe bromodomain is an approximately 110 amino acid module found in histone acetyltransferases and the ATPase component of certain nucleosome remodelling complexes. We report the crystal structure at 1.9 A resolution of the Saccharomyces cerevisiae Gcn5p bromodomain complexed with a peptide corresponding to residues 15-29 of histone H4 acetylated at the zeta-N of lysine 16. We show that this bromodomain preferentially binds to peptides containing an N:-acetyl lysine residue. Only residues 16-19 of the acetylated peptide interact with the bromodomain. The primary interaction is the N:-acetyl lysine binding in a cleft with the specificity provided by the interaction of the amide nitrogen of a conserved asparagine with the oxygen of the acetyl carbonyl group. A network of water-mediated H-bonds with protein main chain carbonyl groups at the base of the cleft contributes to the binding. Additional side chain binding occurs on a shallow depression that is hydrophobic at one end and can accommodate charge interactions at the other. These findings suggest that the Gcn5p bromodomain may discriminate between different acetylated lysine residues depending on the context in which they are displayed. The structural basis for the recognition of acetylated histone H4 by the bromodomain of histone acetyltransferase gcn5p.,Owen DJ, Ornaghi P, Yang JC, Lowe N, Evans PR, Ballario P, Neuhaus D, Filetici P, Travers AA EMBO J. 2000 Nov 15;19(22):6141-9. PMID:11080160[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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