« Previous AbstractEssential Oil Composition of Three Globularia Species    Next AbstractEvolutionary roots of iodine and thyroid hormones in cell-cell signaling »

Proc Natl Acad Sci U S A

Title:		"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"
Author(s):		Crock J; Wildung M; Croteau R;
Address:		"Institute of Biological Chemistry, and Department of Biochemistry and Biophysics, Washington State University, Pullman 99164-6340, USA"
Journal Title:		Proc Natl Acad Sci U S A
Year:		1997
Volume:		94
Issue:		24
Page Number:		12833 - 12838
DOI:		10.1073/pnas.94.24.12833
ISSN/ISBN:		0027-8424 (Print) 1091-6490 (Electronic) 0027-8424 (Linking)
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"
Keywords:		"Amino Acid Sequence Animals Aphids Cloning, Molecular DNA, Complementary Escherichia coli/genetics Mentha piperita Molecular Sequence Data Pheromones/*biosynthesis Plant Extracts/*genetics/metabolism Pyrophosphatases/*genetics Sesquiterpenes/*metabolism;"
Notes:		"MedlineCrock, J Wildung, M Croteau, R eng R37 GM031354/GM/NIGMS NIH HHS/ GM-31354/GM/NIGMS NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. 1997/12/16 Proc Natl Acad Sci U S A. 1997 Nov 25; 94(24):12833-8. doi: 10.1073/pnas.94.24.12833"