Structural insights into selective histone H3 recognition by the human Polybromo bromodomain 2

Cell Res. 2010 May;20(5):529-38. doi: 10.1038/cr.2010.43. Epub 2010 Apr 6.


The Polybromo (PB) protein functions as a key component of the human PBAF chromatin remodeling complex in regulation of gene transcription. PB is made up of modular domains including six bromodomains that are known as acetyl-lysine binding domains. However, histone-binding specificity of the bromodomains of PB has remained elusive. In this study, we report biochemical characterization of all six PB bromodomains' binding to a suite of lysine-acetylated peptides derived from known acetylation sites on human core histones. We demonstrate that bromodomain 2 of PB preferentially recognizes acetylated lysine 14 of histone H3 (H3K14ac), a post-translational mark known for gene transcriptional activation. We further describe the molecular basis of the selective H3K14ac recognition of bromodomain 2 by solving the protein structures in both the free and bound forms using X-ray crystallography and NMR, respectively.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • DNA-Binding Proteins
  • Histones / chemistry
  • Histones / metabolism*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Protein Conformation
  • Protein Structure, Tertiary
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism*


  • DNA-Binding Proteins
  • Histones
  • Nuclear Proteins
  • PBRM1 protein, human
  • Transcription Factors