This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis → Cinnamates Biosynthesis|
Some taxa known to possess this pathway include : Arabidopsis thaliana col
Expected Taxonomic Range: Spermatophyta
The formation of the free hydroxycinnamic acids such as caffeate, ferulate and sinapate has long been thought to derive through a series of hydroxylation and methylation reactions at the phenolic ring of cinnamic acid ( free phenylpropanoid acid biosynthesis) [Baucher98]. However, intensive research directed towards the biosynthesis of phenylpropanoids has led to a significant change of the layout and interconnectivity of this central pathway ( phenylpropanoid biosynthesis) giving rise to the biosynthesis of a vast variety of major secondary metabolites such as flavonoids, lignins, lignans, stilbenes and aurones [Lewis99] [Humphreys02] [Boerjan03].
The discovery of new enzymes involved in the metabolic sequence of phenyplpropanoids caused the revision of the pathway generating ferulate and sinapate (this pathway) which constitute precursors for e.g. hydroxycinnamic esters ( sinapate ester biosynthesis) the main secondary metabolites found in the mustard family [Lorenzen96].
About This Pathway
The main stream in the phenylpropanoid pathway has been demonstrated to lead from p-coumarate to the various monolignols via coumaroyl-CoA and coniferyl aldehyde as the main branching intermediates ( phenylpropanoid biosynthesis). The phenylpropanoid 3-hydroxylation resulting in the formation of 3,4-hydroxylated phenylpropanoids and their further metabolization has been shown to involve hydroxycinnamoyl-CoA esters as substrates [Schoch01] [Franke02] [Hoffmann03] [Hoffmann04] whereas 5-hydroxylation and 5-methylation occur on the level of hydroxycinnamaldehydes and/or hydroxycinnamyl alcohols [Humphreys99] [Osakabe99].
The formation of the free phenylpropanoid acids ferulate and sinapate is catalyzed via the oxidation of the corresponding cinnamaldehydes as proposed earlier [Humphreys99]. The gene (REF1) encoding the enzyme catalyzing the reaction, i.e. cinnamaldehyde dehydrogenase was characterized in Arabidopsis thaliana [Nair04] and shown to possess both coniferyl aldehyde- and sinapyl aldehyde dehydrogenase activity. This enzymatic activity has been found earlier in bacteria where coniferyl aldehyde was converted to ferulate [Achterholt98].
Unification Links: AraCyc:PWY-5168
Achterholt98: Achterholt S, Priefert H, Steinbuchel A (1998). "Purification and characterization of the coniferyl aldehyde dehydrogenase from Pseudomonas sp. Strain HR199 and molecular characterization of the gene." J Bacteriol 1998;180(17);4387-91. PMID: 9721273
Franke02: Franke R, Humphreys JM, Hemm MR, Denault JW, Ruegger MO, Cusumano JC, Chapple C (2002). "The Arabidopsis REF8 gene encodes the 3-hydroxylase of phenylpropanoid metabolism." Plant J 30(1);33-45. PMID: 11967091
Hoffmann03: Hoffmann L, Maury S, Martz F, Geoffroy P, Legrand M (2003). "Purification, cloning, and properties of an acyltransferase controlling shikimate and quinate ester intermediates in phenylpropanoid metabolism." J Biol Chem 278(1);95-103. PMID: 12381722
Hoffmann04: Hoffmann L, Besseau S, Geoffroy P, Ritzenthaler C, Meyer D, Lapierre C, Pollet B, Legrand M (2004). "Silencing of hydroxycinnamoyl-coenzyme A shikimate/quinate hydroxycinnamoyltransferase affects phenylpropanoid biosynthesis." Plant Cell 16(6);1446-65. PMID: 15161961
Humphreys99: Humphreys JM, Hemm MR, Chapple C (1999). "New routes for lignin biosynthesis defined by biochemical characterization of recombinant ferulate 5-hydroxylase, a multifunctional cytochrome P450-dependent monooxygenase." Proc Natl Acad Sci U S A 1999;96(18);10045-50. PMID: 10468559
Lewis99: Lewis NG, Davin LB, Sarkanen S (1999). "The nature and function of lignins." In: Comprehensive natural products chemistry Vol. 3: Barton Sir DHR, Nakanishi K. (eds.-in-chief), Carbohydrates and their derivatives including tannins, cellulose and related lignins. Amsterdam, New York: Elsevier 1999, 617-745.
Lorenzen96: Lorenzen M, Racicot V, Strack D, Chapple C (1996). "Sinapic acid ester metabolism in wild type and a sinapoylglucose-accumulating mutant of arabidopsis." Plant Physiol 112(4);1625-30. PMID: 8972602
Nair04: Nair RB, Bastress KL, Ruegger MO, Denault JW, Chapple C (2004). "The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 gene encodes an aldehyde dehydrogenase involved in ferulic acid and sinapic acid biosynthesis." Plant Cell 16(2);544-54. PMID: 14729911
Osakabe99: Osakabe K, Tsao CC, Li L, Popko JL, Umezawa T, Carraway DT, Smeltzer RH, Joshi CP, Chiang VL (1999). "Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms." Proc Natl Acad Sci U S A 96(16);8955-60. PMID: 10430877
Schoch01: Schoch G, Goepfert S, Morant M, Hehn A, Meyer D, Ullmann P, Werck-Reichhart D (2001). "CYP98A3 from Arabidopsis thaliana is a 3'-hydroxylase of phenolic esters, a missing link in the phenylpropanoid pathway." J Biol Chem 276(39);36566-74. PMID: 11429408
Meyer96: Meyer K, Cusumano JC, Somerville C, Chapple CC (1996). "Ferulate-5-hydroxylase from Arabidopsis thaliana defines a new family of cytochrome P450-dependent monooxygenases." Proc Natl Acad Sci U S A 1996;93(14);6869-74. PMID: 8692910
Muzac00: Muzac I, Wang J, Anzellotti D, Zhang H, Ibrahim RK (2000). "Functional expression of an Arabidopsis cDNA clone encoding a flavonol 3'-O-methyltransferase and characterization of the gene product." Arch Biochem Biophys 2000;375(2);385-8. PMID: 10700397
Rosazza95: Rosazza JP, Huang Z, Dostal L, Volm T, Rousseau B (1995). "Review: biocatalytic transformations of ferulic acid: an abundant aromatic natural product." J Ind Microbiol 15(6);457-71. PMID: 8821508
Zhang97: Zhang H, Wang J, Goodman HM (1997). "An Arabidopsis gene encoding a putative 14-3-3-interacting protein, caffeic acid/5-hydroxyferulic acid O-methyltransferase." Biochim Biophys Acta 1997;1353(3);199-202. PMID: 9349713
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