5g2e | pdb_00005g2e
Structure of the Nap1 H2A H2B complex
Structural highlights
Function[NAP1_YEAST] Acidic protein, which assembles histones into an octamer (in vitro). Involved in the regulation of the localization and the function of the septins during mitosis. Involved in the function of B-type cyclins.[1] [2] [3] [4] [H2B11_XENLA] 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. [H2A1_XENLA] 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. Publication Abstract from PubMedNap1 is a histone chaperone involved in the nuclear import of H2A-H2B and nucleosome assembly. Here, we report the crystal structure of Nap1 bound to H2A-H2B together with in vitro and in vivo functional studies that elucidate the principles underlying Nap1-mediated H2A-H2B chaperoning and nucleosome assembly. A Nap1 dimer provides an acidic binding surface and asymmetrically engages a single H2A-H2B heterodimer. Oligomerization of the Nap1-H2A-H2B complex results in burial of surfaces required for deposition of H2A-H2B into nucleosomes. Chromatin immunoprecipitation-exonuclease (ChIP-exo) analysis shows that Nap1 is required for H2A-H2B deposition across the genome. Mutants that interfere with Nap1 oligomerization exhibit severe nucleosome assembly defects showing that oligomerization is essential for the chaperone function. These findings establish the molecular basis for Nap1-mediated H2A-H2B deposition and nucleosome assembly. Structural evidence for Nap1-dependent H2A-H2B deposition and nucleosome assembly.,Aguilar-Gurrieri C, Larabi A, Vinayachandran V, Patel NA, Yen K, Reja R, Ebong IO, Schoehn G, Robinson CV, Pugh BF, Panne D EMBO J. 2016 Jul 1;35(13):1465-82. doi: 10.15252/embj.201694105. Epub 2016 May, 25. PMID:27225933[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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