2xql

Fitting of the H2A-H2B histones in the electron microscopy map of the complex Nucleoplasmin:H2A-H2B histones (1:5).Fitting of the H2A-H2B histones in the electron microscopy map of the complex Nucleoplasmin:H2A-H2B histones (1:5).

2xql, resolution 19.50Å Show:Asymmetric Unit Biological Assembly Structural highlights 2xql is a 10 chain structure with sequence from Gallus gallus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 19.5Å Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function H2A4_CHICK 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 PubMed Nucleoplasmin (NP) is a pentameric chaperone that regulates the condensation state of chromatin extracting specific basic proteins from sperm chromatin and depositing H2A-H2B histone dimers. It has been proposed that histones could bind to either the lateral or distal face of the pentameric structure. Here, we combine different biochemical and biophysical techniques to show that natural, hyperphosphorylated NP can bind five H2A-H2B dimers and that the amount of bound ligand depends on the overall charge (phosphorylation level) of the chaperone. Three-dimensional reconstruction of NP/H2A-H2B complex carried out by electron microscopy reveals that histones interact with the chaperone distal face. Limited proteolysis and mass spectrometry indicate that the interaction results in protection of the histone fold and most of the H2A and H2B C-terminal tails. This structural information can help to understand the function of NP as a histone chaperone. Nucleoplasmin binds histone H2A-H2B dimers through its distal face.,Ramos I, Martin-Benito J, Finn R, Bretana L, Aloria K, Arizmendi JM, Ausio J, Muga A, Valpuesta JM, Prado A J Biol Chem. 2010 Oct 29;285(44):33771-8. Epub 2010 Aug 9. PMID:20696766 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Histone 3D structures