2igq | pdb_00002igq
Human euchromatic histone methyltransferase 1
Structural highlights
Disease[EHMT1_HUMAN] Defects in EHMT1 are the cause of chromosome 9q subtelomeric deletion syndrome (9q- syndrome) [MIM:610253]. Common features seen in these patients are severe mental retardation, hypotonia, brachy(micro)cephaly, epileptic seizures, flat face with hypertelorism, synophrys, anteverted nares, cupid bow or tented upper lip, everted lower lip, prognathism, macroglossia, conotruncal heart defects, and behavioral problems. Function[EHMT1_HUMAN] Histone methyltransferase that specifically mono- and dimethylates 'Lys-9' of histone H3 (H3K9me1 and H3K9me2, respectively) in euchromatin. H3K9me represents a specific tag for epigenetic transcriptional repression by recruiting HP1 proteins to methylated histones. Also weakly methylates 'Lys-27' of histone H3 (H3K27me). Also required for DNA methylation, the histone methyltransferase activity is not required for DNA methylation, suggesting that these 2 activities function independently. Probably targeted to histone H3 by different DNA-binding proteins like E2F6, MGA, MAX and/or DP1. During G0 phase, it probably contributes to silencing of MYC- and E2F-responsive genes, suggesting a role in G0/G1 transition in cell cycle. In addition to the histone methyltransferase activity, also methylates non-histone proteins: mediates dimethylation of 'Lys-373' of p53/TP53.[1] [2] 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 PubMedSET domain methyltransferases deposit methyl marks on specific histone tail lysine residues and play a major role in epigenetic regulation of gene transcription. We solved the structures of the catalytic domains of GLP, G9a, Suv39H2 and PRDM2, four of the eight known human H3K9 methyltransferases in their apo conformation or in complex with the methyl donating cofactor, and peptide substrates. We analyzed the structural determinants for methylation state specificity, and designed a G9a mutant able to tri-methylate H3K9. We show that the I-SET domain acts as a rigid docking platform, while induced-fit of the Post-SET domain is necessary to achieve a catalytically competent conformation. We also propose a model where long-range electrostatics bring enzyme and histone substrate together, while the presence of an arginine upstream of the target lysine is critical for binding and specificity. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1. Structural biology of human H3K9 methyltransferases.,Wu H, Min J, Lunin VV, Antoshenko T, Dombrovski L, Zeng H, Allali-Hassani A, Campagna-Slater V, Vedadi M, Arrowsmith CH, Plotnikov AN, Schapira M PLoS One. 2010 Jan 11;5(1):e8570. PMID:20084102[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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