The AP2/GCC-box binding domain

Pathogenesis-related genes transcriptional activator binds to the GCC-box pathogenesis-related promoter element and activates the plant's defense genes. Ethylene, chemically the simplest plant hormone, participates in a number of stress responses and developmental processes: e.g., fruit ripening, inhibition of stem and root elongation, promotion of seed germination and flowering, senescence of leaves and flowers, and sex determination [1]. DNA sequence elements that confer ethylene responsiveness have been shown to contain two 11bp GCC boxes, which are necessary and sufficient for transcriptional control by ethylene. Ethylene responsive element binding proteins (EREBPs) have now been identified in a variety of plants. The proteins share a similar domain of around 59 amino acids, which interacts directly with the GCC box in the ERE.

• 1. The ethylene signal transduction pathway in plants.
  Ecker J.R. Science 268: 667- 675 (1995).

Abstract from the SBC paper:

The 3D solution structure of the GCC-box binding domain of a protein from Arabidopsis thaliana in complex with its target DNA fragment has been determined by heteronuclear multidimensional NMR in combination with simulated annealing and restrained molecular dynamic calculation. The domain consists of a three-stranded anti-parallel beta-sheet and an alpha-helix packed approximately parallel to the beta-sheet. Arginine and tryptophan residues in the beta-sheet are identified to contact eight of the nine consecutive base pairs in the major groove, and at the same time bind to the sugar phosphate backbones. The target DNA bends slightly at the central CG step, thereby allowing the DNA to follow the curvature of the beta-sheet.

Allen MD, Yamasaki K, Ohme-Takagi M, Tateno M, Suzuki M (1998) EMBO J., 17 (18), 5484-5496.
A novel mode of DNA recognition by a beta-sheet revealed by the solution structure of the GCC-box binding domain in complex with DNA. PDB:1GCC PDB:2GCC PDB:3GCC