The abscisic acid receptor PYR1 in complex with abscisic acid

Nature. 2009 Dec 3;462(7273):665-8. doi: 10.1038/nature08591. Epub 2009 Nov 8.

Abstract

The plant hormone abscisic acid (ABA) has a central role in coordinating the adaptive response in situations of decreased water availability as well as the regulation of plant growth and development. Recently, a 14-member family of intracellular ABA receptors, named PYR/PYL/RCAR, has been identified. These proteins inhibit in an ABA-dependent manner the activity of a family of key negative regulators of the ABA signalling pathway: the group-A protein phosphatases type 2C (PP2Cs). Here we present the crystal structure of Arabidopsis thaliana PYR1, which consists of a dimer in which one of the subunits is bound to ABA. In the ligand-bound subunit, the loops surrounding the entry to the binding cavity fold over the ABA molecule, enclosing it inside, whereas in the empty subunit they form a channel leaving an open access to the cavity, indicating that conformational changes in these loops have a critical role in the stabilization of the hormone-receptor complex. By providing structural details on the ABA-binding pocket, this work paves the way for the development of new small molecules able to activate the plant stress response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism*
  • Arabidopsis
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / metabolism*
  • Membrane Transport Proteins / chemistry*
  • Membrane Transport Proteins / metabolism*
  • Models, Molecular*
  • Protein Binding
  • Protein Structure, Tertiary

Substances

  • Arabidopsis Proteins
  • Membrane Transport Proteins
  • Pyr1 protein, Arabidopsis
  • Abscisic Acid

Associated data

  • PDB/3K90