| EC |
4.2.3.22 |
| Accepted name: |
germacradienol synthase |
| Reaction: |
(2E,6E)-farnesyl diphosphate + H2O = (1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol + diphosphate |
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For diagram of germacrene-derived sesquiterpenoid biosynthesis, click here |
| Other name(s): |
germacradienol/germacrene-D synthase; 2-trans,6-trans-farnesyl-diphosphate diphosphate-lyase [(1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol-forming] |
| Systematic name: |
(2E,6E)-farnesyl-diphosphate diphosphate-lyase [(1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol-forming] |
| Comments: |
Requires Mg2+ for activity. H-1si of farnesyl diphosphate is lost in the formation of (1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol. Formation of (-)-germacrene D involves a stereospecific 1,3-hydride shift of H-1si of farnesyl diphosphate. Both products are formed from a common intermediate [2]. Other enzymes produce germacrene D as the sole product using a different mechanism. The enzyme mediates a key step in the biosynthesis of geosmin (see EC 4.1.99.16 geosmin synthase), a widely occurring metabolite of many streptomycetes, bacteria and fungi [2]. Also catalyses the reaction of EC 4.2.3.75, (-)-germacrene D synthase. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 211049-88-6 |
| References: |
| 1. |
Cane, D.E. and Watt, R.M. Expression and mechanistic analysis of a germacradienol synthase from Streptomyces coelicolor implicated in geosmin biosynthesis. Proc. Natl. Acad. Sci. USA 100 (2003) 1547–1551. [DOI] [PMID: 12556563] |
| 2. |
He, X. and Cane, D.E. Mechanism and stereochemistry of the germacradienol/germacrene D synthase of Streptomyces coelicolor A3(2). J. Am. Chem. Soc. 126 (2004) 2678–2679. [DOI] [PMID: 14995166] |
| 3. |
Gust, B., Challis, G.L., Fowler, K., Kieser, T. and Chater, K.F. PCR-targeted Streptomyces gene replacement identifies a protein domain
needed for biosynthesis of the sesquiterpene soil odor geosmin. Proc. Natl. Acad. Sci. USA 100 (2003) 1541–1546. [DOI] [PMID: 12563033] |
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| [EC 4.2.3.22 created 2006, modified 2011] |
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