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From Proteopedia
Crystal structure of human lnkH2B-h2A.Z-Anp32e
Structural highlights
FunctionH2AZ_HUMAN Variant histone H2A which replaces conventional H2A in a subset of nucleosomes. 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. May be involved in the formation of constitutive heterochromatin. May be required for chromosome segregation during cell division.[1] H2B2E_HUMAN Core component of nucleosome. 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.[2] [3] [4] Has broad antibacterial activity. May contribute to the formation of the functional antimicrobial barrier of the colonic epithelium, and to the bactericidal activity of amniotic fluid.[5] [6] [7] Publication Abstract from PubMedH2A.Z is a highly conserved histone variant in all species. The chromatin deposition of H2A.Z is specifically catalyzed by the yeast chromatin remodeling complex SWR1 and its mammalian counterpart SRCAP. However, the mechanism by which H2A.Z is preferentially recognized by non-histone proteins remains elusive. Here we identified Anp32e, a novel higher eukaryote-specific histone chaperone for H2A.Z. Anp32e preferentially associates with H2A.Z-H2B dimers rather than H2A-H2B dimers in vitro and in vivo and dissociates non-nucleosomal aggregates formed by DNA and H2A-H2B. We determined the crystal structure of the Anp32e chaperone domain (186-232) in complex with the H2A.Z-H2B dimer. In this structure, the region containing Anp32e residues 214-224, which is absent in other Anp32 family proteins, specifically interacts with the extended H2A.Z alphaC helix, which exhibits an unexpected conformational change. Genome-wide profiling of Anp32e revealed a remarkable co-occupancy between Anp32e and H2A.Z. Cells overexpressing Anp32e displayed a strong global H2A.Z loss at the +1 nucleosomes, whereas cells depleted of Anp32e displayed a moderate global H2A.Z increase at the +1 nucleosomes. This suggests that Anp32e may help to resolve the non-nucleosomal H2A.Z aggregates and also facilitate the removal of H2A.Z at the +1 nucleosomes, and the latter may help RNA polymerase II to pass the first nucleosomal barrier. Anp32e, a higher eukaryotic histone chaperone directs preferential recognition for H2A.Z.,Mao Z, Pan L, Wang W, Sun J, Shan S, Dong Q, Liang X, Dai L, Ding X, Chen S, Zhang Z, Zhu B, Zhou Z Cell Res. 2014 Apr;24(4):389-99. doi: 10.1038/cr.2014.30. Epub 2014 Mar 11. PMID:24613878[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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