Molecular mechanism underlying regulation of chalcone synthase by chalcone isomerase-like protein - PubMed
5 hours ago
- #plant biology
- #enzyme regulation
- #flavonoids
- Flavonoids are crucial for plant growth and environmental adaptation.
- Chalcone synthase (CHS) directs metabolic flux into flavonoid biosynthesis but has catalytic promiscuity.
- Chalcone isomerase-like protein (CHIL) physically interacts with and regulates CHS.
- Crystal structure of CHS-CHIL complex shows CHIL modulates CHS by gating the substrate-binding pocket entrance via its β-hairpin region.
- Molecular dynamics simulations indicate CHIL regulation occurs early in the catalytic cycle.
- CHIL enhances CHS activity and product specificity by promoting CoA release and stabilizing key residues.
- His36 in the β-hairpin is critical; substitution with leucine improves CHS efficiency and specificity.
- This regulatory mechanism is evolutionarily conserved across land plants.
- Engineered CHIL variant (H36E/F37T) significantly enhances CHS activity.
- Findings provide strategies for improving flavonoid production and composition in crops.