Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

The Conserved B3 Domain of VIVIPAROUS1 Has a Cooperative DNA Binding Activity

Masaharu Suzuki, Chien Yuan Kao and Donald R. McCarty
The Plant Cell
Vol. 9, No. 5 (May, 1997), pp. 799-807
DOI: 10.2307/3870433
Stable URL: http://www.jstor.org/stable/3870433
Page Count: 9
  • Read Online (Free)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
The Conserved B3 Domain of VIVIPAROUS1 Has a Cooperative DNA Binding Activity
Preview not available

Abstract

The biochemical activities that underlie the genetically defined activator and repressor functions of the VIVIPAROUS1 (VP1) protein have resisted in vitro analysis. Here, we show that a glutathione S-transferase (GST) fusion protein, including only the highly conserved B3 domain of VP1, has a highly cooperative, sequence-specific DNA binding activity. GST fusion proteins that include larger regions of the VP1 protein have very low activity, indicating that removal of the flanking protein sequences is necessary to elicit DNA binding in vitro. DNA competition and DNase I footprinting analyses show that B3 binds specifically to the Sph element involved in VP1 activation of the C1 gene, whereas binding to the G-box-type VP1-responsive element is of low affinity and is nonspecific. Footprint analysis of the C1 promoter revealed that sequences flanking the core TCCATGCAT motif of Sph also contribute to the recognition of the Sph element in its native context. The salient features of the in vitro GST-B3 DNA interaction are in good agreement with the protein and DNA sequence requirements defined by the functional analyses of VP1 and VP1-responsive elements in maize cells.

Page Thumbnails

  • Thumbnail: Page 
[799]
    [799]
  • Thumbnail: Page 
800
    800
  • Thumbnail: Page 
801
    801
  • Thumbnail: Page 
802
    802
  • Thumbnail: Page 
803
    803
  • Thumbnail: Page 
804
    804
  • Thumbnail: Page 
805
    805
  • Thumbnail: Page 
806
    806
  • Thumbnail: Page 
807
    807