2g6q | pdb_00002g6q
Crystal structure of ING2 PHD finger in complex with H3K4Me3 peptide
Structural highlights
FunctionING2_MOUSE Seems to be involved in p53/TP53 activation and p53/TP53-dependent apoptotic pathways, probably by enhancing acetylation of p53/TP53. Component of a mSin3A-like corepressor complex, which is probably involved in deacetylation of nucleosomal histones. ING2 activity seems to be modulated by binding to phosphoinositides (PtdInsPs) (By similarity). 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 PubMedCovalent modifications of histone tails have a key role in regulating chromatin structure and controlling transcriptional activity. In eukaryotes, histone H3 trimethylated at lysine 4 (H3K4me3) is associated with active chromatin and gene expression. We recently found that plant homeodomain (PHD) finger of tumour suppressor ING2 (inhibitor of growth 2) binds H3K4me3 and represents a new family of modules that target this epigenetic mark. The molecular mechanism of H3K4me3 recognition, however, remains unknown. Here we report a 2.0 A resolution structure of the mouse ING2 PHD finger in complex with a histone H3 peptide trimethylated at lysine 4. The H3K4me3 tail is bound in an extended conformation in a deep and extensive binding site consisting of elements that are conserved among the ING family of proteins. The trimethylammonium group of Lys 4 is recognized by the aromatic side chains of Y215 and W238 residues, whereas the intermolecular hydrogen-bonding and complementary surface interactions, involving Ala 1, Arg 2, Thr 3 and Thr 6 of the peptide, account for the PHD finger's high specificity and affinity. Substitution of the binding site residues disrupts H3K4me3 interaction in vitro and impairs the ability of ING2 to induce apoptosis in vivo. Strong binding of other ING and YNG PHD fingers suggests that the recognition of H3K4me3 histone code is a general feature of the ING/YNG proteins. Elucidation of the mechanisms underlying this novel function of PHD fingers provides a basis for deciphering the role of the ING family of tumour suppressors in chromatin regulation and signalling. Molecular mechanism of histone H3K4me3 recognition by plant homeodomain of ING2.,Pena PV, Davrazou F, Shi X, Walter KL, Verkhusha VV, Gozani O, Zhao R, Kutateladze TG Nature. 2006 Jul 6;442(7098):100-3. Epub 2006 May 21. PMID:16728977[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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