3QN1

Crystal structure of the PYR1 Abscisic Acid receptor in complex with the HAB1 type 2C phosphatase catalytic domain

Summary for 3QN1

• Entry DOI: 10.2210/pdb3qn1/pdb
• Related: 3NJO 3NMT 3k3k 3k90
• Descriptor: Abscisic acid receptor PYR1, Protein phosphatase 2C 16, (2Z,4E)-5-[(1S)-1-hydroxy-2,6,6-trimethyl-4-oxocyclohex-2-en-1-yl]-3-methylpenta-2,4-dienoic acid, ... (5 entities in total)
• Functional Keywords: start domain, bet v domain, pyr/pyl/rcar, pp2c, abscisic acid hormone receptor, type 2c protein phosphatase, plant stress response, abiotic stress, abscisic acid binding, type 2c protein phosphatase binding, intracellular, nucleus, protein binding
• Biological source: Arabidopsis thaliana (mouse-ear cress,thale-cress); More
• Cellular location: Cytoplasm (By similarity): O49686; Cytoplasm: Q9CAJ0
• Total number of polymer chains: 2
• Total formula weight: 59482.30

Authors

Betz, K.,Dupeux, F.,Santiago, J.,Marquez, J.A. (deposition date: 2011-02-07, release date: 2011-03-16, Last modification date: 2023-09-13)

Primary citation

Dupeux, F.,Antoni, R.,Betz, K.,Santiago, J.,Gonzalez-Guzman, M.,Rodriguez, L.,Rubio, S.,Park, S.Y.,Cutler, S.R.,Rodriguez, P.L.,Marquez, J.A.
Modulation of Abscisic Acid Signaling in Vivo by an Engineered Receptor-Insensitive Protein Phosphatase Type 2C Allele.
Plant Physiol., 156:106-116, 2011

PubMed Abstract: The plant hormone abscisic acid (ABA) plays a crucial role in the control of the stress response and the regulation of plant growth and development. ABA binding to PYRABACTIN RESISTANCE1 (PYR1)/PYR1-LIKE (PYL)/REGULATORY COMPONENTS OF ABA RECEPTORS intracellular receptors leads to inhibition of key negative regulators of ABA signaling, i.e. clade A protein phosphatases type 2C (PP2Cs) such as ABA-INSENSITIVE1 and HYPERSENSITIVE TO ABA1 (HAB1), causing the activation of the ABA signaling pathway. To gain further understanding on the mechanism of hormone perception, PP2C inhibition, and its implications for ABA signaling, we have performed a structural and functional analysis of the PYR1-ABA-HAB1 complex. Based on structural data, we generated a gain-of-function mutation in a critical residue of the phosphatase, hab1(W385A), which abolished ABA-dependent receptor-mediated PP2C inhibition without impairing basal PP2C activity. As a result, hab1(W385A) caused constitutive inactivation of the protein kinase OST1 even in the presence of ABA and PYR/PYL proteins, in contrast to the receptor-sensitive HAB1, and therefore hab1(W385A) qualifies as a hypermorphic mutation. Expression of hab1(W385A) in Arabidopsis (Arabidopsis thaliana) plants leads to a strong, dominant ABA insensitivity, which demonstrates that this conserved tryptophan residue can be targeted for the generation of dominant clade A PP2C alleles. Moreover, our data highlight the critical role of molecular interactions mediated by tryptophan-385 equivalent residues for clade A PP2C function in vivo and the mechanism of ABA perception and signaling.

PubMed: 21357183
DOI: 10.1104/pp.110.170894

Experimental method

X-RAY DIFFRACTION (1.8 Å)