title: Structural basis for the interaction of Asf1 with histone H3 and its functional implications.
abstract: Asf1 is a conserved histone chaperone implicated in nucleosome assembly, transcriptional silencing, and the cellular response to DNA damage. We solved the NMR solution structure of the N-terminal functional domain of the human Asf1a isoform, and we identified by NMR chemical shift mapping a surface of Asf1a that binds the C-terminal helix of histone H3. This binding surface forms a highly conserved hydrophobic groove surrounded by charged residues. Mutations within this binding site decreased the affinity of Asf1a for the histone H3/H4 complex in vitro, and the same mutations in the homologous yeast protein led to transcriptional silencing defects, DNA damage sensitivity, and thermosensitive growth. We have thus obtained direct experimental evidence of the mode of binding between a histone and one of its chaperones and genetic data suggesting that this interaction is important in both the DNA damage response and transcriptional silencing.
authors.affiliation: Service de Biophysique des Fonctions Membranaires and Service de Biochimie et de Génétique Moléculaire, Département de Biologie Joliot-Curie, Commissariat à l'Energie Atomique (CEA/Saclay), F-91191 Gif-sur-Yvette, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Mousson
authors.forename: Aurélie
authors.initials: A
authors.lastname: Lautrette
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Thuret
authors.forename: Morgane
authors.initials: M
authors.lastname: Agez
authors.forename: Régis
authors.initials: R
authors.lastname: Courbeyrette
authors.forename: Béatrice
authors.initials: B
authors.lastname: Amigues
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Becker
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Neumann
authors.forename: Raphaël
authors.initials: R
authors.lastname: Guerois
authors.forename: Carl
authors.initials: C
authors.lastname: Mann
authors.forename: Françoise
authors.initials: F
authors.lastname: Ochsenbein
mesh_terms: D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism*; D002645:Chickens; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D018832:Molecular Chaperones; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: C491641:ASF1A protein, human; D018797:Cell Cycle Proteins; D006657:Histones; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D005982:Glutathione Transferase