title: Biosynthetic potential of sesquiterpene synthases: alternative products of tobacco 5-epi-aristolochene synthase.
abstract: Nicotiana tabacum (tobacco) 5-epi-aristolochene synthase (TEAS) serves as an useful model for understanding the enzyme mechanisms of sesquiterpene biosynthesis. Despite extensive bio-chemical and structural characterization of TEAS, a more detailed analysis of the reaction product spectrum is lacking. This study reports the discovery and quantification of several alternative sesquiterpene products generated by recombinant TEAS in the single-vial GC-MS assay. The combined use of chiral and non-polar stationary phases for gas chromatography separations proved critical for resolving the numerous sesquiterpene products of TEAS for mass spectral analysis and identification. Co-injection studies with available authentic standards from both synthetic and natural sources further corroborated the assignment of several compounds, resulting in an annotated reaction mechanism accounting for their biosynthesis. Moreover, a previously undocumented farnesyl trans-cis isomerization pathway was observed.
authors.affiliation: Howard Hughes Medical Institute, The Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: O'Maille
authors.forename: Joe
authors.initials: J
authors.lastname: Chappell
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Noel
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000032:analysis* / Q000737:chemistry*; D012717:Sesquiterpenes / Q000032:analysis* / Q000737:chemistry*; D014026:Nicotiana / Q000201:enzymology*
chemical_list: D012717:Sesquiterpenes; D019883:Alkyl and Aryl Transferases; C078217:5-epi-aristolochene synthase