3mp6
Complex Structure of Sgf29 and dimethylated H3K4
Structural highlights
FunctionMALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.SGF29_YEAST Chromatin reader component of the transcription regulatory histone acetylation (HAT) complexes SAGA and SLIK (PubMed:10026213, PubMed:15647753, PubMed:21685874, PubMed:24307402). In the SAGA complex, SGF29 specifically recognizes and binds methylated 'Lys-4' of histone H3 (H3K4me), with a preference for trimethylated form (H3K4me3) (PubMed:21685874). SGF29 is also required for heterochromatin boundary formation function (PubMed:24307402). 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 (PubMed:10026213). 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) (PubMed:10026213). SAGA acetylates nucleosomal histone H3 to some extent (to form H3K9ac, H3K14ac, H3K18ac and H3K23ac). SAGA interacts with DNA via upstream activating sequences (UASs) (PubMed:10026213). SLIK is proposed to have partly overlapping functions with SAGA (PubMed:15647753). It preferentially acetylates methylated histone H3, at least after activation at the GAL1-10 locus (PubMed:15647753).[1] [2] [3] [4] Publication Abstract from PubMedThe SAGA (Spt-Ada-Gcn5 acetyltransferase) complex is an important chromatin modifying complex that can both acetylate and deubiquitinate histones. Sgf29 is a novel component of the SAGA complex. Here, we report the crystal structures of the tandem Tudor domains of Saccharomyces cerevisiae and human Sgf29 and their complexes with H3K4me2 and H3K4me3 peptides, respectively, and show that Sgf29 selectively binds H3K4me2/3 marks. Our crystal structures reveal that Sgf29 harbours unique tandem Tudor domains in its C-terminus. The tandem Tudor domains in Sgf29 tightly pack against each other face-to-face with each Tudor domain harbouring a negatively charged pocket accommodating the first residue alanine and methylated K4 residue of histone H3, respectively. The H3A1 and K4me3 binding pockets and the limited binding cleft length between these two binding pockets are the structural determinants in conferring the ability of Sgf29 to selectively recognize H3K4me2/3. Our in vitro and in vivo functional assays show that Sgf29 recognizes methylated H3K4 to recruit the SAGA complex to its targets sites and mediates histone H3 acetylation, underscoring the importance of Sgf29 in gene regulation. Sgf29 binds histone H3K4me2/3 and is required for SAGA complex recruitment and histone H3 acetylation.,Bian C, Xu C, Ruan J, Lee KK, Burke TL, Tempel W, Barsyte D, Li J, Wu M, Zhou BO, Fleharty BE, Paulson A, Allali-Hassani A, Zhou JQ, Mer G, Grant PA, Workman JL, Zang J, Min J EMBO J. 2011 Jun 17. doi: 10.1038/emboj.2011.193. PMID:21685874[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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