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Chalcone synthases (CHS) (EC 2.3.1.74) 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.

Schroeder J.

December 2004 / Pattern and text revised.

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

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

Consensus pattern: R-[LIVMFYS]-x-[LIVM]-x-[QHG]-x-G-C-[FYNA]-[GAPV]-G-[GAC]-[STAVK]-x-[LIVMF]-[RAL] C is the active site residue Sequences known to belong to this class detected by the pattern: ALL Other sequence(s) detected in Swiss-Prot: NONE.

• Retrieve an alignment of Swiss-Prot true positive hits:   Clustal format, color, condensed view  / Clustal format, color  / Clustal format, plain text  / Fasta format • Retrieve the sequence logo from the alignment • Taxonomic tree view of all Swiss-Prot/TrEMBL entries matching PS00441 • Retrieve a list of all Swiss-Prot/TrEMBL entries matching PS00441 • Scan Swiss-Prot/TrEMBL entries against PS00441 • view ligand binding statistics

Matching PDB structures: 1CGK 1CGZ 1U0U 1U0V ... [ALL]

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).
	PubMed ID	2033084

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