8DLD

Crystal structure of chalcone-isomerase like protein from Physcomitrella patens (PpCHIL-A)

Summary for 8DLD

• Entry DOI: 10.2210/pdb8dld/pdb
• Descriptor: Chalcone-flavonone isomerase family protein (2 entities in total)
• Functional Keywords: chalcone isomerase-fold, signaling protein
• Biological source: Physcomitrium patens
• Total number of polymer chains: 1
• Total formula weight: 23556.29

Authors

Wolf Saxon, E.,Moorman, C.,Castro, A.,Ruiz, A.,Mallari, J.P.,Burke, J.R. (deposition date: 2022-07-07, release date: 2023-05-10, Last modification date: 2023-11-22)

Primary citation

Wolf-Saxon, E.R.,Moorman, C.C.,Castro, A.,Ruiz-Rivera, A.,Mallari, J.P.,Burke, J.R.
Regulatory ligand binding in plant chalcone isomerase-like (CHIL) proteins.
J.Biol.Chem., 299:104804-104804, 2023

PubMed Abstract: Chalcone isomerase-like (CHIL) protein is a noncatalytic protein that enhances flavonoid content in green plants by serving as a metabolite binder and a rectifier of chalcone synthase (CHS). Rectification of CHS catalysis occurs through direct protein-protein interactions between CHIL and CHS, which alter CHS kinetics and product profiles, favoring naringenin chalcone (NC) production. These discoveries raise questions about how CHIL proteins interact structurally with metabolites and how CHIL-ligand interactions affect interactions with CHS. Using differential scanning fluorimetry on a CHIL protein from Vitis vinifera (VvCHIL), we report that positive thermostability effects are induced by the binding of NC, and negative thermostability effects are induced by the binding of naringenin. NC further causes positive changes to CHIL-CHS binding, whereas naringenin causes negative changes to VvCHIL-CHS binding. These results suggest that CHILs may act as sensors for ligand-mediated pathway feedback by influencing CHS function. The protein X-ray crystal structure of VvCHIL compared with the protein X-ray crystal structure of a CHIL from Physcomitrella patens reveals key amino acid differences at a ligand-binding site of VvCHIL that can be substituted to nullify the destabilizing effect caused by naringenin. Together, these results support a role for CHIL proteins as metabolite sensors that modulate the committed step of the flavonoid pathway.

PubMed: 37172720
DOI: 10.1016/j.jbc.2023.104804

Experimental method

X-RAY DIFFRACTION (1.85 Å)