|PROSITE documentation PDOC00403|
Chalcone synthases (CHS) (EC 126.96.36.199) and stilbene synthases (STS) (formerly known as resveratrol synthases) are related plant enzymes . 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  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:
December 2004 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Schroeder J., Schroeder G.|
|Source||Z. Naturforsch. 45C:1-8(1990).|
|2||Authors||Lanz T., Tropf S., Marner F.-J., Schroeder J., Schroeder G.|
|Title||The role of cysteines in polyketide synthases. Site-directed mutagenesis of resveratrol and chalcone synthases, two key enzymes in different plant-specific pathways.|
|Source||J. Biol. Chem. 266:9971-9976(1991).|