PROSITE documentation PDOC00403
Chalcone and stilbene synthases active site


Chalcone synthases (CHS) (EC and stilbene synthases (STS) (formerly known as resveratrol synthases) are related plant enzymes [1]. CHS is an important enzyme in flavanoid biosynthesis and STS a key enzyme in stilbene-type phyloalexin biosynthesis. Both enzymes catalyze the addition of three molecules of malonyl-CoA to a starter CoA ester (a typical example is 4-coumaroyl-CoA), producing either a chalcone (with CHS) or stilbene (with STS).

These enzymes are proteins of about 390 amino-acid residues. A conserved cysteine residue, located in the central section of these proteins, has been shown [2] to be essential for the catalytic activity of both enzymes and probably represents the binding site for the 4-coumaryl-CoA group. The region around this active site residue is well conserved and can be used as a signature pattern.

In addition to the plant enzymes, this family also includes Bacillus subtilis bcsA.

Expert(s) to contact by email:

Schroeder J.

Last update:

December 2004 / Pattern and text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

CHALCONE_SYNTH, PS00441; Chalcone and stilbene synthases active site  (PATTERN)


1AuthorsSchroeder J. Schroeder G.
SourceZ. Naturforsch. 45C:1-8(1990).

2AuthorsLanz T. Tropf S. Marner F.-J. Schroeder J. Schroeder G.
TitleThe role of cysteines in polyketide synthases. Site-directed mutagenesis of resveratrol and chalcone synthases, two key enzymes in different plant-specific pathways.
SourceJ. Biol. Chem. 266:9971-9976(1991).
PubMed ID2033084

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