1zr5
Crystal structure of the macro-domain of human core histone variant macroH2A1.2Crystal structure of the macro-domain of human core histone variant macroH2A1.2
Structural highlights
FunctionH2AY_HUMAN Variant histone H2A which replaces conventional H2A in a subset of nucleosomes where it represses transcription. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Involved in stable X chromosome inactivation. Inhibits the binding of transcription factors and interferes with the activity of remodeling SWI/SNF complexes. Inhibits histone acetylation by EP300 and recruits class I HDACs, which induces a hypoacetylated state of chromatin. In addition, isoform 1, but not isoform 2, binds ADP-ribose and O-acetyl-ADP-ribose, and may be involved in ADP-ribose-mediated chromatin modulation.[1] [2] [3] [4] [5] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHistone macroH2A is a hallmark of mammalian heterochromatin. Here we show that human macroH2A1.1 binds the SirT1-metabolite O-acetyl-ADP-ribose (OAADPR) through its macro domain. The 1.6-A crystal structure and mutants reveal how the metabolite is recognized. Mutually exclusive exon use in the gene H2AFY produces macroH2A1.2, whose tissue distribution differs. MacroH2A1.2 shows only subtle structural changes but cannot bind nucleotides. Alternative splicing may thus regulate the binding of nicotinamide adenine dinucleotide (NAD) metabolites to chromatin. Splicing regulates NAD metabolite binding to histone macroH2A.,Kustatscher G, Hothorn M, Pugieux C, Scheffzek K, Ladurner AG Nat Struct Mol Biol. 2005 Jul;12(7):624-5. Epub 2005 Jun 19. PMID:15965484[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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