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.
Synonyms: pectin degradation
|Superclasses:||Degradation/Utilization/Assimilation → Carbohydrates Degradation → Sugars Degradation|
Some taxa known to possess this pathway include : Actinidia deliciosa , Arabidopsis thaliana col , Brassica napus , Chamaecyparis obtusa , Citrus sinensis , Cryptomeria japonica , Daucus carota , Gossypium barbadense , Gossypium hirsutum , Malus domestica , Medicago sativa , Nicotiana tabacum , Persea americana , Solanum lycopersicum , Vitis vinifera
Expected Taxonomic Range: Embryophyta
Homogalacturonan (HGA) is a linear chain of 1,4-linked a-D-galacturonic acid residues in which some of the carboxyl groups are methyl esterified. HGA accounts for up to 60% of the pectin found in primary cell walls of all plants. The pectin network is systematically disassembled during many stages of plant development, especially those that require cell separation including fruit ripening, organ abscission, pod and anther dehiscence, and pollen grain maturation. Two major steps are involved in the homogalacturonan disassembling process that requires a methylesterase and a polygalacturonase. The methylesterase prepares deesterified domains of homogalacturonan that can become suitable for the action of polygalacturonase and other pectinolytic enzymes. The deesterified domains of homogalacturonan can also be cross-linked with calcium, resulting in gel formation which contributes to intercellular adhesion.
Unification Links: AraCyc:PWY-1081
Zheng92a: Zheng L, Heupel RC, DellaPenna D (1992). "The beta subunit of tomato fruit polygalacturonase isoenzyme 1: isolation, characterization, and identification of unique structural features." Plant Cell 4(9);1147-56. PMID: 1392611
Hall94: Hall LN, Bird CR, Picton S, Tucker GA, Seymour GB, Grierson D (1994). "Molecular characterisation of cDNA clones representing pectin esterase isozymes from tomato." Plant Mol Biol 25(2);313-8. PMID: 8018878
Lester94: Lester DR, Speirs J, Orr G, Brady CJ (1994). "Peach (Prunus persica) endopolygalacturonase cDNA isolation and mRNA analysis in melting and nonmelting peach cultivars." Plant Physiol 105(1);225-31. PMID: 8029352
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