Chalcone/stilbene synthase, C-terminal Synonym(s): Chalcone synthase, Flavonone synthase, 6'-deoxychalcone synthase <p>Naringenin-chalcone synthases (<db_xref db="EC" dbkey="2.3.1.74"/>) and stilbene synthases (STS) (formerly known as resveratrol synthases) are related plant enzymes. CHS is animportant enzyme in flavanoid biosynthesis and STS is a key enzyme in stilbene-type phyloalexin biosynthesis. Both enzymes catalyze the addition of threemolecules of malonyl-CoA to a starter CoA ester (a typical example is4-coumaroyl-CoA), producing either a chalcone (with CHS) or stilbene (withSTS) [<cite idref="PUB00005665"/>].</p><p>These enzymes have a conserved cysteine residue, located in the central sectionof the protein sequence, which is essential for the catalytic activity of bothenzymes and probably represents the binding site for the 4-coumaryl-CoA group[<cite idref="PUB00002705"/>].</p><p>This domain of chalcone synthase is reported to be structurally similar to domains in thiolase and beta-ketoacyl synthase. The differences in activity are accounted for by differences in the N-terminal domain. </p>