Nucleosome positioning by the winged helix transcription factor HNF3

  1. Eun Yong Shim1,
  2. Christopher Woodcock2, and
  3. Kenneth S. Zaret1,3
  1. 1Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912 USA; 2Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003 USA

Abstract

Nucleosome positioning at genetic regulatory sequences is not well understood. The transcriptional enhancer of the mouse serum albumin gene is active in liver, where regulatory factors occupy their target sites on three nucleosome-like particles designated N1, N2, and N3. The winged helix transcription factor HNF3 binds to two sites near the center of the N1 particle. We created dinucleosome templates using the albumin enhancer sequence and found that site-specific binding of HNF3 protein resulted in nucleosome positioning in vitro similar to that seen in liver nuclei. Thus, binding of a transcription factor can position an underlying nucleosome core.

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Footnotes

  • 3 Corresponding author.

  • E-MAIL zaret{at}brown.edu; FAX (401) 863-1348.

    • Received September 12, 1997.
    • Accepted November 5, 1997.
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