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MetaCyc Enzyme: naringenin chalcone synthase

Gene: CHS Accession Number: G-9303 (MetaCyc)

Synonyms: CHS_H1, chalcone synthase

Species: Humulus lupulus

Summary:
The Humulus lupulus gene CHS_H1 was isolated from the cone of hop plants. The gene was heterologously expressed in Escherichia coli [Okada04]. In the presence of p-coumaryl-CoA, the enzyme produced p-coumaroyltriacetic acid lactone, bis-noryangonin and (2S)-naringenin (which is reported to be produced both spontaneously or via enzymatic conversion [Okada04, Stevens04]). When isovaleryl-CoA is used as start substrate instead of p-coumaryl-CoA, CHS_H1 was shown to produce not only phlorisovalerophenone but also 6-isobutyl-4-hydroxy-2-pyrone, and 6-(4-methyl-2-oxopentyl)-4-hydroxy-2-pyrone [Okada04]. It is important to note however that, although substantial amounts of 6-isobutyl-4-hydroxy-2-pyrone have been detected in the in vitro experiments, this existence of this compound in the hop cone or beer has not been reported, thereby raising the question as to whether it might be an experimental artifact [Okada04].

Citations: [Matousek02]

Molecular Weight of Polypeptide: 42.5 kD (from nucleotide sequence)

Unification Links: Entrez:CAC19808 , ModBase:Q9FEY5 , Protein Model Portal:Q9FEY5 , SMR:Q9FEY5 , Swiss-Model:Q9FEY5 , UniProt:Q9FEY5

Relationship Links: Entrez-Nucleotide:PART-OF:AJ304877 , InterPro:IN-FAMILY:IPR001099 , InterPro:IN-FAMILY:IPR011141 , InterPro:IN-FAMILY:IPR012328 , InterPro:IN-FAMILY:IPR016038 , InterPro:IN-FAMILY:IPR016039 , InterPro:IN-FAMILY:IPR018088 , Pfam:IN-FAMILY:PF00195 , Pfam:IN-FAMILY:PF02797 , Prosite:IN-FAMILY:PS00441

Gene-Reaction Schematic: ?


Enzymatic reaction of: 6-(4-methyl-2-oxopentyl)-4-hydroxy-2-pyrone synthase (naringenin chalcone synthase)

EC Number: 2.3.1.-

isovaleryl-CoA + 3 malonyl-CoA + 2 H+ <=> 6-(4-methyl-2-oxopentyl)-4-hydroxy-2-pyrone + 3 CO2 + 4 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.


Enzymatic reaction of: 6-isobutyl-4-hydroxy-2-pyrone synthase (naringenin chalcone synthase)

EC Number: 2.3.1.-

isovaleryl-CoA + 2 malonyl-CoA + H+ <=> 6-isobutyl-4-hydroxy-2-pyrone + 2 CO2 + 3 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.


Enzymatic reaction of: p-coumaroyltriacetic acid lactone synthase (naringenin chalcone synthase)

EC Number: 2.3.1.-

4-coumaryl-CoA + 3 malonyl-CoA + 2 H+ <=> p-coumaroyltriacetic acid lactone + 3 CO2 + 4 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is favored in the direction shown.


Enzymatic reaction of: coumaroyl-CoA:malonyl-CoA acyltransferase (naringenin chalcone synthase)

EC Number: 2.3.1.-

4-coumaryl-CoA + 2 malonyl-CoA + H+ <=> bis-noryangonin + 2 CO2 + 3 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is favored in the direction shown.


Enzymatic reaction of: isovaleryl-CoA:malonyl-CoA acyltransferase (naringenin chalcone synthase)

EC Number: 2.3.1.156

isovaleryl-CoA + 3 malonyl-CoA + 3 H+ <=> phlorisovalerophenone + 3 CO2 + 4 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: bitter acids biosynthesis , humulone biosynthesis


Enzymatic reaction of: malonyl-CoA:4-coumaroyl-CoA malonyltransferase (cyclizing) (naringenin chalcone synthase)

EC Number: 2.3.1.74

4-coumaryl-CoA + 3 malonyl-CoA + 3 H+ <=> 2',4,4',6'-tetrahydroxychalcone + 3 CO2 + 4 coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: xanthohumol biosynthesis


References

Matousek02: Matousek J., Novak P., Briza J., Patzak J., Niedermeierova H. (2002). "Cloning and characterisation of chs-specific DNA and cDNA sequences from hop (Humulus lupulus L.)." Plant Science 162 : 1007-1018.

Okada04: Okada Y, Sano Y, Kaneko T, Abe I, Noguchi H, Ito K (2004). "Enzymatic reactions by five chalcone synthase homologs from hop (Humulus lupulus L.)." Biosci Biotechnol Biochem 68(5);1142-5. PMID: 15170123

Stevens04: Stevens J.F., Page J.E. (2004). "Xanthohumol and related prenylflavonoids from hops and beer: to your good health!." Phytochemistry 65:1317-1330.


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Mon Nov 24, 2014, biocyc14.