Enzymes
UniProtKB help_outline | 1 proteins |
Enzyme class help_outline |
|
GO Molecular Function help_outline |
|
Reaction participants Show >> << Hide
- Name help_outline (5Z,8Z,11Z,14Z)-eicosatetraenoate Identifier CHEBI:32395 (Beilstein: 5439048) help_outline Charge -1 Formula C20H31O2 InChIKeyhelp_outline YZXBAPSDXZZRGB-DOFZRALJSA-M SMILEShelp_outline CCCCC\C=C/C\C=C/C\C=C/C\C=C/CCCC([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 82 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,648 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (8R)-hydroperoxy-(5Z,9E,11Z,14Z)-eicosatetraenoate Identifier CHEBI:57447 Charge -1 Formula C20H31O4 InChIKeyhelp_outline QQUFCXFFOZDXLA-GTYUHVKWSA-M SMILEShelp_outline CCCCC\C=C/C\C=C/C=C/[C@@H](C\C=C/CCCC([O-])=O)OO 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:14985 | RHEA:14986 | RHEA:14987 | RHEA:14988 | |
---|---|---|---|---|
Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
UniProtKB help_outline |
|
|||
EC numbers help_outline | ||||
Gene Ontology help_outline | ||||
KEGG help_outline | ||||
MetaCyc help_outline |
Related reactions help_outline
More general form(s) of this reaction
Publications
-
Purification and catalytic activities of the two domains of the allene oxide synthase-lipoxygenase fusion protein of the coral Plexaura homomalla.
Boutaud O., Brash A.R.
The conversion of fatty acid hydroperoxides to allene epoxides is catalyzed by a cytochrome P450 in plants and, in coral, by a 43-kDa catalase-related hemoprotein fused to the lipoxygenase that synthesizes the 8R-hydroperoxyeicosatetraenoic acid (8R-HPETE) substrate. We have expressed the separate ... >> More
The conversion of fatty acid hydroperoxides to allene epoxides is catalyzed by a cytochrome P450 in plants and, in coral, by a 43-kDa catalase-related hemoprotein fused to the lipoxygenase that synthesizes the 8R-hydroperoxyeicosatetraenoic acid (8R-HPETE) substrate. We have expressed the separate lipoxygenase and allene oxide synthase (AOS) domains of the coral protein in Escherichia coli (BL21 cells) and purified the proteins; this system gives high expression (1.5 and 0.3 micromol/liter, respectively) of catalytically active enzymes. Both domains show fast reaction kinetics. Catalytic activity of the lipoxygenase domain is stimulated 5-fold by high concentrations of monovalent cations (500 mM Na(+), Li(+), or K(+)), and an additional 5-fold by 10 mM Ca(2+). The resulting rates of reaction are approximately 300 turnovers/s, 1-2 orders of magnitude faster than mammalian lipoxygenases. This makes the coral lipoxygenase well suited for partnership with the AOS domain, which shows maximum rates of approximately 1400 turnovers/s in the conversion of 8R-HPETE to the allene oxide. Some unusual catalytic activities of the two domains are described. The lipoxygenase domain converts 20.3omega6 partly to the bis-allylic hydroperoxide (10-hydroperoxyeicosa-8,11,14-trienoic acid). Metabolism of the preferred substrate of the AOS domain, 8R-HPETE, is inhibited by the enantiomer 8S-HPETE. Although the AOS domain has homology to catalase in primary structure, it is completely lacking in catalatic action on H(2)O(2); catalase itself, as expected from its preference for small hydroperoxides, is ineffective in allene oxide synthesis from 8R-HPETE. << Less
J. Biol. Chem. 274:33764-33770(1999) [PubMed] [EuropePMC]
This publication is cited by 6 other entries.
-
Identification of a naturally occurring peroxidase-lipoxygenase fusion protein.
Koljak R., Boutaud O., Shieh B.-H., Samel N., Brash A.R.
A distant relative of catalase that is specialized for metabolism of a fatty acid hydroperoxide was identified. This heme peroxidase occurs in coral as part of a fusion protein, the other component of which is a lipoxygenase that forms the hydroperoxide substrate. The end product is an unstable ep ... >> More
A distant relative of catalase that is specialized for metabolism of a fatty acid hydroperoxide was identified. This heme peroxidase occurs in coral as part of a fusion protein, the other component of which is a lipoxygenase that forms the hydroperoxide substrate. The end product is an unstable epoxide (an allene oxide) that is a potential precursor of prostaglandin-like molecules. These results extend the known chemistry of catalase-like proteins and reveal a distinct type of enzymatic construct involved in the metabolism of polyunsaturated fatty acids. << Less
Science 277:1994-1996(1997) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.
-
Discovery of an arachidonic acid C-8 lipoxygenase in the gorgonian coral Pseudoplexaura porosa.
Bundy G.L., Nidy E.G., Epps D.E., Mizsak S.A., Wnuk R.J.
The gorgonian coral Pseudoplexaura porosa contains a lipoxygenase capable of converting exogenous arachidonic acid into (8R)-8-hydroperoxy-5,9,11,14-eicosatetraenoic acid. The (8R)-(or 8-L-) configuration in this product, opposite to that observed in previously reported 8-lipoxygenase products, wa ... >> More
The gorgonian coral Pseudoplexaura porosa contains a lipoxygenase capable of converting exogenous arachidonic acid into (8R)-8-hydroperoxy-5,9,11,14-eicosatetraenoic acid. The (8R)-(or 8-L-) configuration in this product, opposite to that observed in previously reported 8-lipoxygenase products, was determined unambiguously by comparison of oxidative ozonolysis fragments with authentic malic acid-derived standards. Extracts from the coral contained no detectable prostaglandins (PGAs, PGBs, PGEs, or PGFs). Although arachidonic acid represents one of the most abundant of the common fatty acids found in the phospholipid and total lipid fractions of P. porosa, products ascribable to the arachidonic acid 8-lipoxygenase pathway ((8R)-8-hydroperoxy-5,9,11,14-eicosatetraenoic acid, the corresponding alcohol 8-hydroxyeicosatetraenoic acid, further transformation products) have not yet been identified in the coral extracts. The physiological significance of the 8-lipoxygenase in this species remains a matter for speculation. << Less
J Biol Chem 261:747-751(1986) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
-
The structure of coral allene oxide synthase reveals a catalase adapted for metabolism of a fatty acid hydroperoxide.
Oldham M.L., Brash A.R., Newcomer M.E.
8R-Lipoxygenase and allene oxide synthase (AOS) are parts of a naturally occurring fusion protein from the coral Plexaura homomalla. AOS catalyses the production of an unstable epoxide (an allene oxide) from the fatty acid hydroperoxide generated by the lipoxygenase activity. Here, we report the s ... >> More
8R-Lipoxygenase and allene oxide synthase (AOS) are parts of a naturally occurring fusion protein from the coral Plexaura homomalla. AOS catalyses the production of an unstable epoxide (an allene oxide) from the fatty acid hydroperoxide generated by the lipoxygenase activity. Here, we report the structure of the AOS domain and its striking structural homology to catalase. Whereas nominal sequence identity between the enzymes had been previously described, the extent of structural homology observed was not anticipated, given that this enzyme activity had been exclusively associated with the P450 superfamily, and conservation of a catalase fold without catalase activity is unprecedented. Whereas the heme environment is largely conserved, the AOS heme is planar and the distal histidine is flanked by two hydrogen-bonding residues. These critical differences likely facilitate the switch from a catalatic activity to that of a fatty acid hydroperoxidase. << Less
Proc. Natl. Acad. Sci. U.S.A. 102:297-302(2005) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.