3JRS image
Deposition Date 2009-09-08
Release Date 2009-11-03
Last Version Date 2024-03-20
Entry Detail
PDB ID:
3JRS
Title:
Crystal structure of (+)-ABA-bound PYL1
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.05 Å
R-Value Free:
0.22
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 41 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Putative uncharacterized protein At5g46790
Gene (Uniprot):PYL1
Chain IDs:A, B, C
Chain Length:208
Number of Molecules:3
Biological Source:Arabidopsis thaliana
Ligand Molecules
Primary Citation

Abstact

The phytohormone abscisic acid (ABA) mediates the adaptation of plants to environmental stresses such as drought and regulates developmental signals such as seed maturation. Within plants, the PYR/PYL/RCAR family of START proteins receives ABA to inhibit the phosphatase activity of the group-A protein phosphatases 2C (PP2Cs), which are major negative regulators in ABA signalling. Here we present the crystal structures of the ABA receptor PYL1 bound with (+)-ABA, and the complex formed by the further binding of (+)-ABA-bound PYL1 with the PP2C protein ABI1. PYL1 binds (+)-ABA using the START-protein-specific ligand-binding site, thereby forming a hydrophobic pocket on the surface of the closed lid. (+)-ABA-bound PYL1 tightly interacts with a PP2C domain of ABI1 by using the hydrophobic pocket to cover the active site of ABI1 like a plug. Our results reveal the structural basis of the mechanism of (+)-ABA-dependent inhibition of ABI1 by PYL1 in ABA signalling.

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Primary Citation of related structures