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  • The EMBO Journal (1997) 16, 3974 - 3986
  • doi:10.1093/emboj/16.13.3974

Subtle hydrophobic interactions between the seventh residue of the zinc finger loop and the first base of an HGATAR sequence determine promoter-specific recognition by the Aspergillus nidulans GATA factor AreA

Adriana Ravagnani1,2, Lisette Gorfinkiel3,4,10, Timothy Langdon1,5,10, George Diallinas3,6, Elisabeth Adjadj7, Stéphane Demais3, Diana Gorton8,9, Herbert N. Arst Jr1 and Claudio Scazzocchio3,8

  1. Department of Infectious Diseases and Bacteriology, Royal Postgraduate Medical School, Ducane Road, London W12 0NN, UK
  2. Present address: Institute of Biological Sciences, University of Wales, Aberystwyth, Dyfed SY23 3DA, UK
  3. Institut de Génétique et Microbiologie, Unité de Recherche Associé au CNRS, 1354, Bâtiment 409, Université Paris-Sud, Centre d'Orsay, France
  4. Present address: Seccion Bioquímica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
  5. Present address: Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Dyfed SY23 3EB, UK
  6. Present address: Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, PO Box 1527, Heraklion, 71 110, Crete, Greece
  7. U350 INSERM, Institut Curie, Centre Universitaire, Bâtiment 112, 91405 Orsay Cedex, France
  8. Department of Biology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, Essex, UK
  9. Present address: Enfield and Haringey Health Authority, Alexandra Place, Lower Park Road, London N11 1ST, UK
  10. L.Gorfinkiel and T.Langdon contributed equally to this work

Received 24 January 1997; Revised 14 March 1997

A change of a universally conserved leucine to valine in the DNA-binding domain of the GATA factor AreA results in inability to activate some AreA-dependent promoters, including that of the uapA gene encoding a specific urate–xanthine permease. Some other AreA- dependent promoters become able to function more efficiently than in the wild-type context. A methionine in the same position results in a less extreme, but opposite effect. Suppressors of the AreA(Val) mutation mapping in the uapA promoter show that the nature of the base in the first position of an HGATAR (where H stands for A, T or C) sequence determines the relative affinity of the promoter for the wild-type and mutant forms of AreA. In vitro binding studies of wild-type and mutant AreA proteins are completely consistent with the phenotypes in vivo. Molecular models of the wild-type and mutant AreA–DNA complexes derived from the atomic coordinates of the GATA-1–AGATAA complex account both for the phenotypes observed in vivo and the binding differences observed in vitro. Our work extends the consensus of physiologically relevant binding sites from WGATAR to HGATAR, and provides a rationale for the almost universal evolutionary conservation of leucine at the seventh position of the Zn finger of GATA factors. This work shows inter alia that the sequence CGATAGagAGATAA, comprising two almost adjacent AreA-binding sites, is sufficient to ensure activation of transcription of the uapA gene.

  • Keywords:

    • Aspergillus nidulans,
    • GATA transcription factors,
    • molecular modelling,
    • promoter recognition