4JYP

crystal Structure of KAI2 Apo form

Summary for 4JYP

• Entry DOI: 10.2210/pdb4jyp/pdb
• Related: 4JYM
• Descriptor: Hydrolase, alpha/beta fold family protein (2 entities in total)
• Functional Keywords: alpha/beta hydrolase, hydrolase
• Biological source: Arabidopsis thaliana (mouse-ear cress,thale-cress)
• Cellular location: Nucleus: Q9SZU7
• Total number of polymer chains: 2
• Total formula weight: 59631.83

Authors

Guo, Y.,Zheng, Z.,Noel, J.P. (deposition date: 2013-03-31, release date: 2013-05-08, Last modification date: 2024-02-28)

Primary citation

Guo, Y.,Zheng, Z.,La Clair, J.J.,Chory, J.,Noel, J.P.
Smoke-derived karrikin perception by the alpha/beta-hydrolase KAI2 from Arabidopsis.
Proc.Natl.Acad.Sci.USA, 110:8284-8289, 2013

PubMed Abstract: Genetic studies in Arabidopsis implicate an α/β-hydrolase, KARRIKIN-INSENSITIVE 2 (KAI2) as a receptor for karrikins, germination-promoting butenolide small molecules found in the smoke of burned plants. However, direct biochemical evidence for the interaction between KAI2 and karrikin and for the mechanism of downstream signaling by a KAI2-karrikin complex remain elusive. We report crystallographic analyses and ligand-binding experiments for KAI2 recognition of karrikins. The karrikin-1 (KAR1) ligand sits in the opening to the active site abutting a helical domain insert but distal from the canonical catalytic triad (Ser95-His246-Asp217) of α/β-hydrolases, consistent with the lack of detectable hydrolytic activity by purified KAI2. The closest approach of KAR1 to Ser95-His246-Asp217 is 3.8 Å from His246. Six aromatic side chains, including His246, encapsulate KAR1 through geometrically defined aromatic-aromatic interactions. KAR1 binding induces a conformational change in KAI2 at the active site entrance. A crevice of hydrophobic residues linking the polar edge of KAR1 and the helical domain insert suggests that KAI2-KAR1 creates a contiguous interface for binding signaling partners in a ligand-dependent manner.

PubMed: 23613584
DOI: 10.1073/pnas.1306265110

Experimental method

X-RAY DIFFRACTION (1.3 Å)