8VCZ

Crystal Structure of KAI2 from Oryza sativa

Summary for 8VCZ

• Entry DOI: 10.2210/pdb8vcz/pdb
• Descriptor: Probable esterase D14L (2 entities in total)
• Functional Keywords: karrikin, signalling, alpha/beta-hydrolase, rice, hydrolase
• Biological source: Oryza sativa (Asian cultivated rice)
• Total number of polymer chains: 1
• Total formula weight: 29746.97

Authors

Gilio, A.K.,Shabek, N.,Guercio, A.M.,Pawlak, J. (deposition date: 2023-12-14, release date: 2024-07-31, Last modification date: 2024-08-21)

Primary citation

Guercio, A.M.,Gilio, A.K.,Pawlak, J.,Shabek, N.
Structural insights into rice KAI2 receptor provide functional implications for perception and signal transduction.
J.Biol.Chem., 300:107593-107593, 2024

PubMed Abstract: KAI2 receptors, classified as plant α/β hydrolase enzymes, are capable of perceiving smoke-derived butenolide signals and endogenous yet unidentified KAI2-ligands (KLs). While the number of functional KAI2 receptors varies among land plant species, rice has only one KAI2 gene. Rice, a significant crop and representative of grasses, relies on KAI2-mediated Arbuscular mycorrhiza (AM) symbioses to flourish in traditionally arid and nutrient-poor environments. This study presents the first crystal structure of an active rice (Oryza sativa, Os) KAI2 hydrolase receptor. Our structural and biochemical analyses uncover grass-unique pocket residues influencing ligand sensitivity and hydrolytic activity. Through structure-guided analysis, we identify a specific residue whose mutation enables the increase or decrease of ligand perception, catalytic activity, and signal transduction. Furthermore, we investigate OsKAI2-mediated signaling by examining its ability to form a complex with its binding partner, the F-box protein DWARF3 (D3) ubiquitin ligase and subsequent degradation of the target substrate OsSMAX1, demonstrating the significant role of hydrophobic interactions in the OsKAI2-D3 interface. This study provides new insights into the diverse and pivotal roles of the OsKAI2 signaling pathway in the plant kingdom, particularly in grasses.

PubMed: 39032651
DOI: 10.1016/j.jbc.2024.107593

Experimental method

X-RAY DIFFRACTION (1.68 Å)