Biology:Chalcone isomerase
| Chalcone isomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 chalcone isomerase complexed with 4'-hydroxyflavanone | |||||||||
| Identifiers | |||||||||
| Symbol | Chalcone | ||||||||
| Pfam | PF02431 | ||||||||
| InterPro | IPR003466 | ||||||||
| SCOP2 | 1eyp / SCOPe / SUPFAM | ||||||||
| |||||||||
Chalcone isomerase (EC 5.5.1.6) is an enzyme that catalyzes the general chemical reaction
- a chalcone a flavanone
In the biosynthesis of anthocyanins in plants, an important example of this reaction converts the chalcone produced by chalcone synthase to naringenin:[1][2]
This reaction can occur spontaneously but provides racemic material. The enzyme constrains the reaction to give only the (S) isomer of the flavanone.[1][3]
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).[4]
References
- ↑ 1.0 1.1 Enzyme 5.5.1.6 at KEGG Pathway Database.
- ↑ Ververidis Filippos, F; Trantas Emmanouil; Douglas Carl; Vollmer Guenter; Kretzschmar Georg; Panopoulos Nickolas (October 2007). "Biotechnology of flavonoids and other phenylpropanoid-derived natural products. Part I: Chemical diversity, impacts on plant biology and human health". Biotechnology Journal 2 (10): 1214–34. doi:10.1002/biot.200700084. PMID 17935117.
- ↑ "Purification and properties of chalcone-flavanone isomerase from soya bean seed". Phytochemistry 6 (5): 625–632. 1967. doi:10.1016/S0031-9422(00)86001-X. Bibcode: 1967PChem...6..625M.
- ↑ "Structure and mechanism of the evolutionarily unique plant enzyme chalcone isomerase". Nat. Struct. Biol. 7 (9): 786–91. September 2000. doi:10.1038/79025. PMID 10966651.
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