InterPro domain: IPR001099

Chalcone synthases (CHS) ( 2.3.1.74 ) and stilbene synthases (STS) (formerly known as resveratrol synthases) are related plant enzymes, members of the plant polyketide synthase superfamily. CHS is an important enzyme in flavonoid biosynthesis and STS is a key enzyme in stilbene-type phyloalexin biosynthesis. Both enzymes catalyse 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) [ 1 ].

These enzymes have a conserved cysteine residue, located in the central section of the protein sequence, which is essential for the catalytic activity of both enzymes and probably represents the binding site for the 4-coumaryl-CoA group [ 2 , 3 ].

This entry represents the N-terminal domain of chalcone and stilbene synthases and related proteins.

1. Stilbene and chalcone synthases: related enzymes with key functions in plant-specific pathways. Z. Naturforsch., C, J. Biosci. 45, 1-8
2. The role of cysteines in polyketide synthases. Site-directed mutagenesis of resveratrol and chalcone synthases, two key enzymes in different plant-specific pathways. J. Biol. Chem. 266, 9971-6
3. Chalcone synthase and its functions in plant resistance. Phytochem Rev 10, 397-412