Chalcone synthase (CHS) is pivotal for the biosynthesis of flavonoid antimicrobial phytoalexins and anthocyanin pigments in plants. It produces chalcone by condensing one p-coumaroyl- and three malonyl-coenzyme A thioesters into a polyketide reaction intermediate that cyclises without the involvement of specific catalytic residues.
Defined by 4 residues: CYS:A-164PHE:A-215HIS:A-303ASN:A-336