2idc
From Proteopedia
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Structure of the Histone H3-Asf1 Chaperone Interaction
Overview
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.
About this Structure
2IDC is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Tue Jan 29 20:39:16 2008
Categories: Saccharomyces cerevisiae | Single protein | Antczak, A.J. | Berger, J.M. | Kaufman, P.D. | Tsubota, T. | Asf1 | Chaperone | Chromatin | H3 | Histone | Ig-like fold