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Isolation and bacterial expression of a sesquiterpene synthase cDNA clone from peppermint (Mentha x piperita, L.) that produces the aphid alarm pheromone (E)-beta-farnesene.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1997 Nov 25; Vol. 94 (24), pp. 12833-8. - Publication Year :
- 1997
-
Abstract
- (E)-beta-Farnesene is a sesquiterpene semiochemical that is used extensively by both plants and insects for communication. This acyclic olefin is found in the essential oil of peppermint (Mentha x piperita) and can be synthesized from farnesyl diphosphate by a cell-free extract of peppermint secretory gland cells. A cDNA from peppermint encoding (E)-beta-farnesene synthase was cloned by random sequencing of an oil gland library and was expressed in Escherichia coli. The corresponding synthase has a deduced size of 63.8 kDa and requires a divalent cation for catalysis (Km for Mg2+ approximately 150 microM; Km for Mn2+ approximately 7 microM). The sesquiterpenoids produced by the recombinant enzyme, as determined by radio-GC and GC-MS, are (E)-beta-farnesene (85%), (Z)-beta-farnesene (8%), and delta-cadinene (5%) with the native C15 substrate farnesyl diphosphate (Km approximately 0.6 microM; Vrel = 100) and Mg2+ as cofactor, and (E)-beta-farnesene (98%) and (Z)-beta-farnesene (2%) with Mn2+ as cofactor (Vrel = 80). With the C10 analog, GDP, as substrate (Km = 1.5 microM; Vrel = 3 with Mg2+ as cofactor), the monoterpenes limonene (48%), terpinolene (15%), and myrcene (15%) are produced.
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 94
- Issue :
- 24
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 9371761
- Full Text :
- https://doi.org/10.1073/pnas.94.24.12833