Enzymes
| UniProtKB help_outline | 1 proteins |
| Enzyme class help_outline |
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- Name help_outline 3β-hydroxy-9β-pimara-7,15-dien-19,6β-olide Identifier CHEBI:49195 (Beilstein: 1261198) help_outline Charge 0 Formula C20H28O3 InChIKeyhelp_outline SPZLJXUKZRAIQP-KSYFULEYSA-N SMILEShelp_outline [H][C@@]12OC(=O)[C@@]3(C)[C@@H](O)CC[C@](C)([C@]4([H])CC[C@](C)(CC4=C1)C=C)[C@@]23[H] 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NAD+ Identifier CHEBI:57540 (Beilstein: 3868403) help_outline Charge -1 Formula C21H26N7O14P2 InChIKeyhelp_outline BAWFJGJZGIEFAR-NNYOXOHSSA-M SMILEShelp_outline NC(=O)c1ccc[n+](c1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,142 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline momilactone A Identifier CHEBI:49191 (Beilstein: 1689564; CAS: 51415-07-7) help_outline Charge 0 Formula C20H26O3 InChIKeyhelp_outline MPHXYQVSOFGNEN-JGHPTVLTSA-N SMILEShelp_outline [H][C@@]12OC(=O)[C@@]3(C)C(=O)CC[C@](C)([C@]4([H])CC[C@](C)(CC4=C1)C=C)[C@@]23[H] 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADH Identifier CHEBI:57945 (Beilstein: 3869564) help_outline Charge -2 Formula C21H27N7O14P2 InChIKeyhelp_outline BOPGDPNILDQYTO-NNYOXOHSSA-L SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,073 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:25363 | RHEA:25364 | RHEA:25365 | RHEA:25366 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Biosynthesis of rice phytoalexin: enzymatic conversion of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide to momilactone A.
Atawong A., Hasegawa M., Kodama O.
Momilactone A, a major rice diterpene phytoalexin, could be synthesized by dehydrogenation at the 3-position of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide in rice leaves. The presence of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide in UV-irradiated rice leaves was confirmed by comp ... >> More
Momilactone A, a major rice diterpene phytoalexin, could be synthesized by dehydrogenation at the 3-position of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide in rice leaves. The presence of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide in UV-irradiated rice leaves was confirmed by comparing the mass spectra and retention times after a GC/MS analysis of the natural and synthetic compounds. The soluble protein fraction from UV-irradiated rice leaves showed dehydrogenase activity to convert 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide into momilactone A. The enzyme required NAD+ or NADP+ as a hydrogen acceptor. The optimum pH for the reaction was 8. The Km value to 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide was 36 microM when NAD+ was supplied as a cofactor at a concentration of 1 mM. 3fl-Hydroxy-9beta-pimara-7,15-dien-19,6beta-olide and its dehydrogenase activity were induced in a time-dependent manner by UV irradiation. << Less
Biosci. Biotechnol. Biochem. 66:566-570(2002) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Identification of a biosynthetic gene cluster in rice for momilactones.
Shimura K., Okada A., Okada K., Jikumaru Y., Ko K.-W., Toyomasu T., Sassa T., Hasegawa M., Kodama O., Shibuya N., Koga J., Nojiri H., Yamane H.
Rice diterpenoid phytoalexins such as momilactones and phytocassanes are produced in suspension-cultured rice cells treated with a chitin oligosaccharide elicitor and in rice leaves irradiated with UV light. The common substrate geranylgeranyl diphosphate is converted into diterpene hydrocarbon pr ... >> More
Rice diterpenoid phytoalexins such as momilactones and phytocassanes are produced in suspension-cultured rice cells treated with a chitin oligosaccharide elicitor and in rice leaves irradiated with UV light. The common substrate geranylgeranyl diphosphate is converted into diterpene hydrocarbon precursors via a two-step sequential cyclization and then into the bioactive phytoalexins via several oxidation steps. It has been suggested that microsomal cytochrome P-450 monooxygenases (P-450s) are involved in the downstream oxidation of the diterpene hydrocarbons leading to the phytoalexins and that a dehydrogenase is involved in momilactone biosynthesis. However, none of the enzymes involved in the downstream oxidation of the diterpene hydrocarbons have been identified. In this study, we found that a putative dehydrogenase gene (AK103462) and two functionally unknown P-450 genes (CYP99A2 and CYP99A3) form a chitin oligosaccharide elicitor- and UV-inducible gene cluster, together with OsKS4 and OsCyc1, the diterpene cyclase genes involved in momilactone biosynthesis. Functional analysis by heterologous expression in Escherichia coli followed by enzyme assays demonstrated that the AK103462 protein catalyzes the conversion of 3beta-hydroxy-9betaH-pimara-7,15-dien-19,6beta-olide into momilactone A. The double knockdown of CYP99A2 and CYP99A3 specifically suppressed the elicitor-inducible production of momilactones, strongly suggesting that CYP99A2, CYP99A3, or both are involved in momilactone biosynthesis. These results provide strong evidence for the presence on chromosome 4 of a gene cluster involved in momilactone biosynthesis. << Less
J. Biol. Chem. 282:34013-34018(2007) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.