2idc

Structure of the Histone H3-Asf1 Chaperone Interaction

spinqualitylabelsall models 2idc, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2idc is a 1 chain structure with sequence from Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ASF1_YEAST Histone chaperone that facilitates histone deposition and histone exchange and removal during nucleosome assembly and disassembly. Facilitates histone deposition through both replication-dependent and replication-independent chromatin assembly pathways. Cooperates with chromatin assembly factor 1 (CAF-1) to promote replication-dependent chromatin assembly and with the HIR complex to promote replication-independent chromatin assembly, which may occur during transcription and DNA repair. May be required for the maintenance of a subset of replication elongation factors, including DNA polymerase epsilon, the RFC complex and PCNA, at stalled replication forks. Also required for acetylation of histone H3 on 'Lys-9' and 'Lys-56'. H3_YEAST Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: The histone H3/H4 chaperone Asf1 (anti-silencing function 1) is required for the establishment and maintenance of proper chromatin structure, as well as for genome stability in eukaryotes. Asf1 participates in both DNA replication-coupled (RC) and replication-independent (RI) histone deposition reactions in vitro and interacts with complexes responsible for both pathways in vivo. Asf1 is known to directly bind histone H3, however, high-resolution structural information about the geometry of this interaction was previously unknown. RESULTS: Here we report the structure of a histone/histone chaperone interaction. We have solved the 2.2 A crystal structure of the conserved N-terminal immunoglobulin fold domain of yeast Asf1 (residues 2-155) bound to the C-terminal helix of yeast histone H3 (residues 121-134). The structure defines a histone-binding patch on Asf1 consisting of both conserved and yeast-specific residues; mutation of these residues abrogates H3/H4 binding affinity. The geometry of the interaction indicates that Asf1 binds to histones H3/H4 in a manner that likely blocks sterically the H3/H3 interface of the nucleosomal four-helix bundle. CONCLUSION: These data clarify how Asf1 regulates histone stoichiometry to modulate epigenetic inheritance. The structure further suggests a physical model in which Asf1 contributes to interpretation of a "histone H3 barcode" for sorting H3 isoforms into different deposition pathways. Structure of the yeast histone H3-ASF1 interaction: implications for chaperone mechanism, species-specific interactions, and epigenetics.,Antczak AJ, Tsubota T, Kaufman PD, Berger JM BMC Struct Biol. 2006 Dec 13;6:26. PMID:17166288 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Anti-silencing factor 3D structures

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