7u53

Nucleosome core particle with AP-site at SHL0

spinqualitylabelsall models 7u53, resolution 4.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7u53 is a 10 chain structure with sequence from Homo sapiens and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 4Å Ligands: 3DR Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function H32_HUMAN Publication Abstract from PubMed Genomic DNA is continually exposed to endogenous and exogenous factors that promote DNA damage. Eukaryotic genomic DNA is packaged into nucleosomes, which present a barrier to accessing and effectively repairing DNA damage. The mechanisms by which DNA repair proteins overcome this barrier to repair DNA damage in the nucleosome and protect genomic stability is unknown. Here, we determine how the base excision repair (BER) endonuclease AP-endonuclease 1 (APE1) recognizes and cleaves DNA damage in the nucleosome. Kinetic assays determine that APE1 cleaves solvent-exposed AP sites in the nucleosome with 3 - 6 orders of magnitude higher efficiency than occluded AP sites. A cryo-electron microscopy structure of APE1 bound to a nucleosome containing a solvent-exposed AP site reveal that APE1 uses a DNA sculpting mechanism for AP site recognition, where APE1 bends the nucleosomal DNA to access the AP site. Notably, additional biochemical and structural characterization of occluded AP sites identify contacts between the nucleosomal DNA and histone octamer that prevent efficient processing of the AP site by APE1. These findings provide a rationale for the position-dependent activity of BER proteins in the nucleosome and suggests the ability of BER proteins to sculpt nucleosomal DNA drives efficient BER in chromatin. Structural basis for APE1 processing DNA damage in the nucleosome.,Weaver TM, Hoitsma NM, Spencer JJ, Gakhar L, Schnicker NJ, Freudenthal BD Nat Commun. 2022 Sep 14;13(1):5390. doi: 10.1038/s41467-022-33057-7. PMID:36104361 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Histone 3D structures

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