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: 9-LOX and 9-HPL pathway, 9-oxo-nonanoate biosynthesis
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Fatty Acid Derivatives Biosynthesis|
Expected Taxonomic Range: Viridiplantae
Lipoxygenases (LOX) are nonheme iron-containing enzymes that catalyze the dioxygenation of fatty acids with a 1,4-pentadiene structure and are ubiquitous among eukaryotes. In plants, LOX enzymes are known to insert oxygen at position C-9 (9-LOX) or position C-13 (13-LOX) (counting from the carboxylate group) of linoleate and α-linolenate, the most abundant fatty acids in plant membrane lipids [Bachmann02]. In several plants,
The oxygen is inserted into one of the carbons that participate in the cis double bonds of the substrate. During the process that bond is moved to a neighboring carbon and changes to a trans configuration. So, for example, linoleate ((9Z,12Z)-octadeca-9,12-dienoate) becomes 9(S)-hydroperoxy-10(E),12(Z)-octadecadienoate via 9-LOX activity, and (13S)-HPODE via 13-LOX activity. In plants, most reported LOXs are 13-LOXs, which are important in the biosynthesis of plant hormone jasmonic acid.
The hydroperoxide intermediates can be converted to aldehydes and oxoacids by hydroperoxide lyases (HPL). HPLs are divided into two groups, 9-HPL and 13-HPL, depending on their substrate preferences, either being 9-hydroperoxides, or 13-hydroperoxides. The aldehydes produced by 9-HPL are known as defense compounds, as well as special flavors. For example, (2E)-nonenal gives the cardboard flavor of aged beer, and the off-flavor of aged milled rice. 9-HPL activity has only been reported from a few plant species including rice and cucumber.
Superpathways: superpathway of lipoxygenase
Bachmann02: Bachmann A, Hause B, Maucher H, Garbe E, Voros K, Weichert H, Wasternack C, Feussner I (2002). "Jasmonate-induced lipid peroxidation in barley leaves initiated by distinct 13-LOX forms of chloroplasts." Biol Chem 383(10);1645-57. PMID: 12452441
Kuroda05: Kuroda H, Oshima T, Kaneda H, Takashio M (2005). "Identification and functional analyses of two cDNAs that encode fatty acid 9-/13-hydroperoxide lyase (CYP74C) in rice." Biosci Biotechnol Biochem 69(8);1545-54. PMID: 16116284
Noordermeer01: Noordermeer MA, Veldink GA, Vliegenthart JF (2001). "Fatty acid hydroperoxide lyase: a plant cytochrome p450 enzyme involved in wound healing and pest resistance." Chembiochem 2(7-8);494-504. PMID: 11828481
Boeglin08: Boeglin WE, Itoh A, Zheng Y, Coffa G, Howe GA, Brash AR (2008). "Investigation of substrate binding and product stereochemistry issues in two linoleate 9-lipoxygenases." Lipids 43(11);979-87. PMID: 18795358
Hughes01a: Hughes RK, West SI, Hornostaj AR, Lawson DM, Fairhurst SA, Sanchez RO, Hough P, Robinson BH, Casey R (2001). "Probing a novel potato lipoxygenase with dual positional specificity reveals primary determinants of substrate binding and requirements for a surface hydrophobic loop and has implications for the role of lipoxygenases in tubers." Biochem J 353(Pt 2);345-55. PMID: 11139400
Royo96: Royo J, Vancanneyt G, Perez AG, Sanz C, Stormann K, Rosahl S, Sanchez-Serrano JJ (1996). "Characterization of three potato lipoxygenases with distinct enzymatic activities and different organ-specific and wound-regulated expression patterns." J Biol Chem 271(35);21012-9. PMID: 8702864
Vellosillo07: Vellosillo T, Martinez M, Lopez MA, Vicente J, Cascon T, Dolan L, Hamberg M, Castresana C (2007). "Oxylipins produced by the 9-lipoxygenase pathway in Arabidopsis regulate lateral root development and defense responses through a specific signaling cascade." Plant Cell 19(3);831-46. PMID: 17369372
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