A lock that cuts its own key

As a general rule, ligands bind to their cognate receptor noncovalently and induce a conformational change in the receptor that activates the receptor or enables it to interact with binding partners. Yao et al. and de Saint Germain et al. report that the α/β hydrolase DWARF14 (D14) is a strigolactone receptor, and this unusual receptor not only hydrolyzes its ligand but also forms a covalent attachment to the modified ligand. Strigolactones are carotenoid-derived plant hormones that regulate many developmental processes and trigger the germination of parasitic plants. One of the molecular processes triggered by strigolactones is the proteasomal degradation of D14. Orthologs of D14 from Arabidopsis thaliana (thale cress, Yao et al.), Pisum sativum (pea, de Saint Germain et al.), and Oryza sativa (rice, de Saint Germain et al.) hydrolyzed biologically active strigolactones and became covalently bound to one of the hydrolysis products. Through structural analysis of Arabidopsis D14 (AtD14) in complex with two of the proteins that promote its degradation, Yao et al. found that becoming covalently attached to the strigolactone hydrolysis product elicited a conformational change in AtD14 that enabled AtD14 to interact with its binding partners. Arabidopsis d14-5 mutants display phenotypes characteristic of impaired strigolactone signaling and have a single amino acid substitution in AtD14 that was predicted to affect a structural feature that is involved in the strigolac...
Source: Signal Transduction Knowledge Environment - Category: Science Authors: Tags: STKE Editors ' Choice Source Type: news