FACT Disrupts Nucleosome Structure by Binding H2A-H2B with Conserved Peptide Motifs

David J Kemble; Laura L McCullough; Frank G Whitby; Tim Formosa; Christopher P Hill

doi:10.1016/j.molcel.2015.09.008

FACT Disrupts Nucleosome Structure by Binding H2A-H2B with Conserved Peptide Motifs

Mol Cell. 2015 Oct 15;60(2):294-306. doi: 10.1016/j.molcel.2015.09.008. Epub 2015 Oct 8.

Authors

David J Kemble¹, Laura L McCullough¹, Frank G Whitby¹, Tim Formosa², Christopher P Hill³

Affiliations

¹ Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112-5650, USA.
² Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112-5650, USA. Electronic address: tim@biochem.utah.edu.
³ Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112-5650, USA. Electronic address: chris@biochem.utah.edu.

Abstract

FACT, a heterodimer of Spt16 and Pob3, is an essential histone chaperone. We show that the H2A-H2B binding activity that is central to FACT function resides in short acidic regions near the C termini of each subunit. Mutations throughout these regions affect binding and cause correlated phenotypes that range from mild to lethal, with the largest individual contributions unexpectedly coming from an aromatic residue and a nearby carboxylate residue within each domain. Spt16 and Pob3 bind overlapping sites on H2A-H2B, and Spt16-Pob3 heterodimers simultaneously bind two H2A-H2B dimers, the same stoichiometry as the components of a nucleosome. An Spt16:H2A-H2B crystal structure explains the biochemical and genetic data, provides a model for Pob3 binding, and implies a mechanism for FACT reorganization that we confirm biochemically. Moreover, unexpected similarity to binding of ANP32E and Swr1 with H2A.Z-H2B reveals that diverse H2A-H2B chaperones use common mechanisms of histone binding and regulating nucleosome functions.

Keywords: Spt16-Pob3; crystal structure; histone binding; histone chaperone; nucleosome reorganization.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Amino Acid Motifs
Conserved Sequence
Crystallography, X-Ray
DNA-Binding Proteins / chemistry
DNA-Binding Proteins / genetics
DNA-Binding Proteins / metabolism*
Gene Expression Regulation, Fungal
High Mobility Group Proteins / chemistry
High Mobility Group Proteins / genetics
High Mobility Group Proteins / metabolism*
Histones / chemistry
Histones / genetics
Histones / metabolism*
Models, Molecular
Molecular Sequence Data
Nucleosomes / chemistry*
Nucleosomes / metabolism
Protein Binding
Protein Multimerization
Saccharomyces cerevisiae / genetics*
Saccharomyces cerevisiae / metabolism
Saccharomyces cerevisiae Proteins / chemistry
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism*
Sequence Alignment
Transcription Factors / chemistry
Transcription Factors / genetics
Transcription Factors / metabolism*
Transcriptional Elongation Factors / chemistry
Transcriptional Elongation Factors / genetics
Transcriptional Elongation Factors / metabolism*

Substances

DNA-Binding Proteins
FACT protein, S cerevisiae
High Mobility Group Proteins
Histones
Nucleosomes
POB3 protein, S cerevisiae
SPT16 protein, S cerevisiae
Saccharomyces cerevisiae Proteins
Transcription Factors
Transcriptional Elongation Factors

Abstract

Publication types

MeSH terms

Substances

Grants and funding