Enzymes
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Reaction participants Show >> << Hide
- Name help_outline (1S,4aS)-1,4a-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalene Identifier CHEBI:61680 Charge 0 Formula C12H20 InChIKeyhelp_outline HDVGBFCTHLFNEE-ASKATJPDSA-N SMILEShelp_outline C[C@H]1CCC[C@@]2(C)CCC=CC12 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 H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (−)-geosmin Identifier CHEBI:46702 (Beilstein: 4656415,2410491; CAS: 19700-21-1) help_outline Charge 0 Formula C12H22O InChIKeyhelp_outline JLPUXFOGCDVKGO-TUAOUCFPSA-N SMILEShelp_outline C[C@H]1CCC[C@@]2(C)CCCC[C@]12O 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
Cross-references
| RHEA:30455 | RHEA:30456 | RHEA:30457 | RHEA:30458 | |
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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 the earthy odorant geosmin by a bifunctional Streptomyces coelicolor enzyme.
Jiang J., He X., Cane D.E.
Geosmin is responsible for the characteristic odor of moist soil, as well as off-flavors in drinking water and foodstuffs. Geosmin is generated from farnesyl diphosphate (FPP, 2) by an enzyme that is encoded by the SCO6073 gene in the soil organism Streptomyces coelicolor A32 (ref. 3). We have now ... >> More
Geosmin is responsible for the characteristic odor of moist soil, as well as off-flavors in drinking water and foodstuffs. Geosmin is generated from farnesyl diphosphate (FPP, 2) by an enzyme that is encoded by the SCO6073 gene in the soil organism Streptomyces coelicolor A32 (ref. 3). We have now shown that the recombinant N-terminal half of this protein catalyzes the Mg2+-dependent cyclization of FPP to germacradienol and germacrene D, while the highly homologous C-terminal domain, previously thought to be catalytically silent, catalyzes the Mg2+-dependent conversion of germacradienol to geosmin. Site-directed mutagenesis confirmed that the N- and C-terminal domains each harbor a distinct, independently functioning active site. A mutation in the N-terminal domain of germacradienol-geosmin synthase of a catalytically essential serine to alanine results in the conversion of FPP to a mixture of sesquiterpenes that includes an aberrant product identified as isolepidozene, which was previously suggested to be an enzyme-bound intermediate in the cyclization of FPP to germacradienol. << Less
Nat Chem Biol 3:711-715(2007) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Geosmin biosynthesis in Streptomyces avermitilis. Molecular cloning, expression, and mechanistic study of the germacradienol/geosmin synthase.
Cane D.E., He X., Kobayashi S., Omura S., Ikeda H.
Geosmin (1) is responsible for the characteristic odor of moist soil. The Gram-positive soil bacterium Streptomyces avermitilis produces geosmin (1) as well as its precursor germacradienol (3). The S. avermitilis gene SAV2163 (geoA) is extremely similar to the S. coelicolor A3(2) SCO6073 gene that ... >> More
Geosmin (1) is responsible for the characteristic odor of moist soil. The Gram-positive soil bacterium Streptomyces avermitilis produces geosmin (1) as well as its precursor germacradienol (3). The S. avermitilis gene SAV2163 (geoA) is extremely similar to the S. coelicolor A3(2) SCO6073 gene that encodes a germacradienol/geosmin synthase. S. avermitilis mutants with a deleted geoA were unable to produce either germacradienol (3) or geosmin (1). Biosynthesis of both compounds was restored by introducing an intact geoA gene into the mutants. Incubation of recombinant GeoA, encoded by the SAV2163 gene of S. avermitilis, with farnesyl diphosphate (2) in the presence of Mg2+ gave a mixture of (4S,7R)-germacra-1(10)E,5E-diene-11-ol (3) (66%), (7S)-germacrene D (4) (24%), geosmin (1) (8%), and a hydrocarbon, tentatively assigned the structure of octalin 5 (2%). Incubation of this germacradienol/geosmin synthase with [1,1-(2)H2] FPP (2a) gave geosmin-d1 (1a), as predicted. When recombinant GeoA from either S. avermitilis or S. coelicolor A3(2) was incubated with nerolidyl diphosphate (8), only the acyclic elimination products beta3-farnesene (10), (Z)-alpha-farnesene (11), and (E)-alpha-farnesene (12) were formed, thereby ruling out nerolidyl diphosphate as an intermediate in the conversion of farnesyl diphosphate to geosmin, germacradienol, and germacrene D. << Less
J Antibiot (Tokyo) 59:471-479(2006) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Geosmin biosynthesis. Streptomyces coelicolor germacradienol/germacrene D synthase converts farnesyl diphosphate to geosmin.
Jiang J., He X., Cane D.E.
Geosmin is responsible for the characteristic odor of moist soil. Incubation of recombinant germacradienol synthase, encoded by the SCO6073 (SC9B1.20) gene of the Gram-positive soil bacterium Streptomyces coelicolor, with farnesyl diphosphate (2, FPP) in the presence of Mg2+ gave a mixture of (4S, ... >> More
Geosmin is responsible for the characteristic odor of moist soil. Incubation of recombinant germacradienol synthase, encoded by the SCO6073 (SC9B1.20) gene of the Gram-positive soil bacterium Streptomyces coelicolor, with farnesyl diphosphate (2, FPP) in the presence of Mg2+ gave a mixture of (4S,7R)-germacra-1(10)E,5E-diene-11-ol (3) (74%), (-)-(7S)-germacrene D (4) (10%), geosmin (1) (13%), and a hydrocarbon, tentatively assigned the structure of octalin 5 (3%). Individual incubations of recombinant germacradienol synthase with [1,1-2H2]FPP (2a), (1R)-[1-2H]-FPP (2b), and (1S)-[1-2H]-FPP (2c), as well as with FPP (2) in D2O, and GC-MS analysis of the resulting deuterated products supported a mechanism of geosmin formation involving proton-initiated cyclization and retro-Prins fragmentation of the initially formed germacradienol to give intermediate 5, followed by protonation of 5, 1,2-hydride shift, and capture of water. << Less
J. Am. Chem. Soc. 128:8128-8129(2006) [PubMed] [EuropePMC]
This publication is cited by 4 other entries.