title: Theoretical and experimental analysis of the reaction mechanism of MrTPS2, a triquinane-forming sesquiterpene synthase from chamomile.
abstract: Terpene synthases, as key enzymes of terpene biosynthesis, have garnered the attention of chemists and biologists for many years. Their carbocationic reaction mechanisms are responsible for the huge variety of terpene structures in nature. These mechanisms are amenable to study by using classical biochemical approaches as well as computational analysis, and in this study we combine quantum-chemical calculations and deuterium-labeling experiments to elucidate the reaction mechanism of a triquinane forming sesquiterpene synthase from chamomile. Our results suggest that the reaction from farnesyl diphosphate to triquinanes proceeds through caryophyllyl and presilphiperfolanyl cations and involves the protonation of a stable (-)-(E)-β-caryophyllene intermediate. A tyrosine residue was identified that appears to be involved in the proton-transfer process.
authors: Department of Chemistry, University of California Davis, 1 Shields Avenue, Davis, CA 95616 (USA).
authors: Young J
authors: YJ
authors: Hong
authors: Sandra
authors: S
authors: Irmisch
authors: Selina C
authors: SC
authors: Wang
authors: Stefan
authors: S
authors: Garms
authors: Jonathan
authors: J
authors: Gershenzon
authors: Liansuo
authors: L
authors: Zu
authors: Tobias G
authors: TG
authors: Köllner
authors: Dean J
authors: DJ
authors: Tantillo
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000096:biosynthesis* / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D020843:Chamomile / Q000737:chemistry*; D015394:Molecular Structure; D000081223:Polycyclic Sesquiterpenes; D011522:Protons; D011789:Quantum Theory; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D002412:Cations; D000081223:Polycyclic Sesquiterpenes; D011522:Protons; D012717:Sesquiterpenes; C024714:caryophyllene; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase
keywords: biosynthesis; carbocations; density functional calculations; natural products; reaction mechanisms; terpenoids