Molecular Cloning and Characterization of a Linalool Synthase from Lemon Myrtle

• Published in: Bioscience, biotechnology, and biochemistry Vol. 75; no. 7; pp. 1245 - 1248
• Main Authors: SUGIURA, Mizue, ITO, Sohei, SAITO, Yosuke, NIWA, Yasuo, KOLTUNOW, Anna M., SUGIMOTO, Osamu, SAKAI, Hiroshi
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 2011; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Backhousia citriodora; Biological and medical sciences; Citrus - enzymology; Citrus - genetics; Citrus - metabolism; Cloning, Molecular - methods; DNA, Complementary - chemistry; DNA, Complementary - genetics; Escherichia coli; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Hydro-Lyases - chemistry; Hydro-Lyases - genetics; Kinetics; linalool synthase; monoterpene synthase; Monoterpenes - metabolism; Myrtus - enzymology; Myrtus - genetics; Myrtus - metabolism; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; TPSb subfamily; Characterization; TPSb subfamily; Enzyme; linalool synthase; Monoterpene; Synthase; Molecular cloning; Backhousia citriodora; monoterpene synthase
• ISSN: 0916-8451; 1347-6947; 1347-6947
• DOI: 10.1271/bbb.100922

Using a homology-based PCR strategy, we identified a cDNA with sequence similarity to linalool synthase from lemon myrtle. Functional expression of the cDNA (designated BcLS) gene in Escherichia coli yielded an active enzyme capable of catalyzing the conversion of geranyl diphosphate to (−)-linalool, i.e., an acyclic monoterpene alcohol, and to lesser amounts of cyclic monoterpenes. The kinetic parameters of BcLS were similar to those of synthases producing cyclic monoterpenes. PCR analysis revealed that the BcLS gene transcript was ubiquitously expressed in lemon myrtle and was upregulated in response to jasmonic acid treatment. Although the physiological role of neryl diphosphate (NPP) dependency of BcLS remains unclear, the cyclization activity of BcLS was enhanced when NPP was used as substrate, resulting in predominant production of cyclic monoterpenes. These findings indicate that BcLS has novel specificity and kinetic parameters, but its physiological responses to stresses such as insect damage appear to be similar to known linalool synthases.