Chalcone isomerase
In enzymology, a chalcone isomerase (EC 5.5.1.6) is an enzyme that catalyzes the chemical reaction
- a chalcone a flavanone
| chalcone isomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 5.5.1.6 | ||||||||
| CAS no. | 9073-57-8 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| Chalcone isomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 chalcone isomerase complexed with 4'-hydroxyflavanone | |||||||||
| Identifiers | |||||||||
| Symbol | Chalcone | ||||||||
| Pfam | PF02431 | ||||||||
| InterPro | IPR003466 | ||||||||
| SCOP2 | 1eyp / SCOPe / SUPFAM | ||||||||
| |||||||||
Hence, this enzyme has one substrate, a chalcone, and one product, a flavanone.
This enzyme belongs to the family of isomerases, specifically the class of intramolecular lyases. The systematic name of this enzyme class is flavanone lyase (decyclizing). This enzyme is also called chalcone-flavanone isomerase. This enzyme participates in flavonoid biosynthesis.
The Petunia hybrida (Petunia) genome contains two genes coding for very similar enzymes, ChiA and ChiB, but only the first seems to encode a functional chalcone isomerase.
Structural studies
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1EYP, 1EYQ, 1FM7, 1FM8, 1JEP, 1JX0, and 1JX1.
Chalcone isomerase has a core 2-layer alpha/beta structure consisting of beta(3)-alpha(2)-beta-alpha(2)-beta(3).[1]
References
Further reading
- Moustafa E, Wong E (1967). "Purification and properties of chalcone-flavanone isomerase from soya bean seed". Phytochemistry. 6 (5): 625–632. doi:10.1016/S0031-9422(00)86001-X.