3swc
GLP (G9a-like protein) SET domain in complex with Dnmt3aK44me2 peptideGLP (G9a-like protein) SET domain in complex with Dnmt3aK44me2 peptide
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] Publication Abstract from PubMedDNA CpG methylation and histone H3 lysine 9 (H3K9) methylation are two major repressive epigenetic modifications, and these methylations are positively correlated with one another in chromatin. Here we show that G9a or G9a-like protein (GLP) dimethylate the amino-terminal lysine 44 (K44) of mouse Dnmt3a (equivalent to K47 of human DNMT3A) in vitro and in cells overexpressing G9a or GLP. The chromodomain of MPP8 recognizes the dimethylated Dnmt3aK44me2. MPP8 also interacts with self-methylated GLP in a methylation-dependent manner. The MPP8 chromodomain forms a dimer in solution and in crystals, suggesting that a dimeric MPP8 molecule could bridge the methylated Dnmt3a and GLP, resulting in a silencing complex of Dnmt3a-MPP8-GLP/G9a on chromatin templates. Together, these findings provide a molecular explanation, at least in part, for the co-occurrence of DNA methylation and H3K9 methylation in chromatin. MPP8 mediates the interactions between DNA methyltransferase Dnmt3a and H3K9 methyltransferase GLP/G9a.,Chang Y, Sun L, Kokura K, Horton JR, Fukuda M, Espejo A, Izumi V, Koomen JM, Bedford MT, Zhang X, Shinkai Y, Fang J, Cheng X Nat Commun. 2011 Nov 15;2:533. doi: 10.1038/ncomms1549. PMID:22086334[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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