The plant zinc finger protein ZPT2-2 has a unique mode of DNA interaction

J Biol Chem. 2001 Sep 21;276(38):35802-7. doi: 10.1074/jbc.M104079200. Epub 2001 Jul 13.

Abstract

ZPT2-2 is a DNA-binding protein of petunia that contains two canonical TFIIIA-type zinc finger motifs separated by a long linker. We previously reported that ZPT2-2 bound to two separate AGT core sites, with each zinc finger making contact with each core site. Here we present our further characterization of ZPT2-2 by using selected and amplified binding sequence imprinting and surface plasmon resonance analyses; together, these assays revealed some unusual features of the interaction between ZPT2-2 and DNA. These experiments allowed us to conclude that 1) the optimal binding sequence for the N-terminal zinc finger is AGC(T), and that of the C-terminal one is CAGT; 2) multiple arrangements of the two core sites accommodate binding; and 3) the spacing between the two core sites affects the binding affinity. In light of these observations, we propose a new model for the DNA-ZPT2-2 interaction. Further, consistent with this model, a high affinity binding site for ZPT2-2 was found in the promoter region of the ZPT2-2 gene. This site may serve as a cis-element for the autoregulation of ZPT2-2 gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • DNA / metabolism*
  • DNA Probes
  • Molecular Sequence Data
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*
  • Plants / chemistry*
  • Protein Binding
  • Zinc Fingers*

Substances

  • DNA Probes
  • Plant Proteins
  • DNA