Publication Date:
2009-10-27
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Miyazono, Ken-Ichi -- Miyakawa, Takuya -- Sawano, Yoriko -- Kubota, Keiko -- Kang, Hee-Jin -- Asano, Atsuko -- Miyauchi, Yumiko -- Takahashi, Mihoko -- Zhi, Yuehua -- Fujita, Yasunari -- Yoshida, Takuya -- Kodaira, Ken-Suke -- Yamaguchi-Shinozaki, Kazuko -- Tanokura, Masaru -- England -- Nature. 2009 Dec 3;462(7273):609-14. doi: 10.1038/nature08583.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19855379" target="_blank"〉PubMed〈/a〉
Keywords:
Abscisic Acid/*physiology
;
Arabidopsis/*physiology
;
Arabidopsis Proteins/*chemistry/*metabolism
;
Binding Sites
;
*Models, Molecular
;
Protein Binding
;
Protein Structure, Tertiary
;
Recombinant Proteins/chemistry/metabolism
;
*Signal Transduction
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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