Chalcone isomerase

Chalcone isomerase
Identifiers
EC no.5.5.1.6
CAS no.9073-57-8
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Search
PMCarticles
PubMedarticles
NCBIproteins
Chalcone isomerase
chalcone isomerase complexed with 4'-hydroxyflavanone
Identifiers
SymbolChalcone
PfamPF02431
InterProIPR003466
SCOP21eyp / SCOPe / SUPFAM
Available protein structures:
PDB  IPR003466 PF02431 (ECOD; PDBsum)  
AlphaFold

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. ^ a b Enzyme 5.5.1.6 at KEGG Pathway Database.
  2. ^ 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.
  3. ^ Moustafa E, Wong E (1967). "Purification and properties of chalcone-flavanone isomerase from soya bean seed". Phytochemistry. 6 (5): 625–632. Bibcode:1967PChem...6..625M. doi:10.1016/S0031-9422(00)86001-X.
  4. ^ Jez JM, Bowman ME, Dixon RA, Noel JP (September 2000). "Structure and mechanism of the evolutionarily unique plant enzyme chalcone isomerase". Nat. Struct. Biol. 7 (9): 786–91. doi:10.1038/79025. PMID 10966651. S2CID 22198011.
This article incorporates text from the public domain Pfam and InterPro: IPR003466