Title

Histone H3-K56 acetylation is catalyzed by histone chaperone-dependent complexes

PubMed ID

17320445

UMMS Affiliation

Program in Gene Function and Expression

Date

2-27-2007

Document Type

Article

Subjects

Acetylation; Amino Acid Sequence; Amino Acids; Animals; Catalysis; Cell Cycle Proteins; Chickens; Coenzymes; DNA, Fungal; Histone Acetyltransferases; Histones; Kinetics; Lysine; Mass Spectrometry; Molecular Chaperones; Molecular Sequence Data; Multiprotein Complexes; Protein Binding; Protein Subunits; Recombinant Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Substrate Specificity

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Acetylation of histone H3 on lysine 56 occurs during mitotic and meiotic S phase in fungal species. This acetylation blocks a direct electrostatic interaction between histone H3 and nucleosomal DNA, and the absence of this modification is associated with extreme sensitivity to genotoxic agents. We show here that H3-K56 acetylation is catalyzed when Rtt109, a protein that lacks significant homology to known acetyltransferases, forms an active complex with either of two histone binding proteins, Asf1 or Vps75. Rtt109 binds to both these cofactors, but not to histones alone, forming enzyme complexes with kinetic parameters similar to those of known histone acetyltransferase (HAT) enzymes. Therefore, H3-K56 acetylation is catalyzed by a previously unknown mechanism that requires a complex of two proteins: Rtt109 and a histone chaperone. Additionally, these complexes are functionally distinct, with the Rtt109/Asf1 complex, but not the Rtt109/Vps75 complex, being critical for resistance to genotoxic agents.

Rights and Permissions

Citation: Mol Cell. 2007 Mar 9;25(5):703-12. Epub 2007 Feb 22. Link to article on publisher's site

Related Resources

Link to Article in PubMed