ACF1 improves the effectiveness of nucleosome mobilization by ISWI through PHD-histone contacts

EMBO J. 2004 Oct 13;23(20):4029-39. doi: 10.1038/sj.emboj.7600382. Epub 2004 Sep 30.


The nucleosome remodelling ATPase ISWI resides in several distinct protein complexes whose subunit composition reflects their functional specialization. Association of ISWI with ACF1, the largest subunit of CHRAC and ACF complexes, improves the efficiency of ISWI-induced nucleosome mobilization by an order of magnitude and also modulates the reaction qualitatively. In order to understand the principle by which ACF1 improves the efficiency of ISWI, we mapped their mutual interaction requirements and generated a series of ACF complexes lacking conserved ACF1 domains. Deletion of the C-terminal PHD finger modules of ACF1 or their disruption by zinc chelation profoundly affected the nucleosome mobilization capability of associated ISWI in trans. Interactions of the PHD fingers with the central domains of core histones contribute significantly to the binding of ACF to the nucleosome substrate, suggesting a novel role for PHD modules as nucleosome interaction determinants. Connecting ACF to histones may be prerequisite for efficient conversion of ATP-dependent conformational changes of ISWI into translocation of DNA relative to the histones during nucleosome mobilization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / isolation & purification
  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Baculoviridae / genetics
  • Chromatin / chemistry
  • Drosophila
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / isolation & purification
  • Drosophila Proteins / metabolism*
  • Escherichia coli / genetics
  • Glutathione Transferase / metabolism
  • Histones / metabolism*
  • Insect Proteins / metabolism*
  • Insecta / cytology
  • Models, Biological
  • Nucleosomes / metabolism*
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*


  • Acf protein, Drosophila
  • Chromatin
  • Drosophila Proteins
  • Histones
  • Insect Proteins
  • Nucleosomes
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Glutathione Transferase
  • Adenosine Triphosphatases