In Arabidopsis thaliana, the Sigma factor B regulator RsbQ-like family of alpha/beta hydrolases contains the strigolactone (SL) receptor DWARF14 (AtD14), the karrikin receptor KARRIKIN INSENSITIVE2 (AtKAI2), and DWARF14-LIKE2 (AtDLK2), a protein of unknown function. Despite very similar protein folds, AtD14 and AtKAI2 differ in size and architecture of their ligand binding pockets, influencing their substrate specificity. We present the 1.5 A crystal structure of AtDLK2, revealing the smallest ligand binding pocket in the protein family, bordered by two unique glycine residues. We identified a gatekeeper residue in the protein's lid domain and present a pyrrolo-quinoline-dione compound that inhibits AtDLK2's enzymatic activity.
Burger M, Honda K, Kondoh Y, Hong S, Watanabe N, Osada H, Chory J (2022) Crystal structure of Arabidopsis DWARF14-LIKE2 (DLK2) reveals a distinct substrate binding pocket architecture Plant Direct6: e446
Burger M, Honda K, Kondoh Y, Hong S, Watanabe N, Osada H, Chory J (2022) Plant Direct6: e446