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J Am Chem Soc

Title:		"Probing the mechanism of 1,4-conjugate elimination reactions catalyzed by terpene synthases"
Author(s):		Faraldos JA; Gonzalez V; Li A; Yu F; Koksal M; Christianson DW; Allemann RK;
Address:		"School of Chemistry and Cardiff Catalysis Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, United Kingdom"
Journal Title:		J Am Chem Soc
Year:		2012
Volume:		20121211
Issue:		51
Page Number:		20844 - 20848
DOI:		10.1021/ja311022s
ISSN/ISBN:		1520-5126 (Electronic) 0002-7863 (Print) 0002-7863 (Linking)
Abstract:		"The reaction mechanisms of (E)-beta-farnesene synthase (EBFS) and isoprene synthase (ISPS), enzymes that catalyze a formal regiospecific 1,4-conjugate elimination of hydrogen diphosphate from (E,E)-farnesyl and dimethylallyl diphosphate (FDP and DMADP) to generate the semiochemicals (E)-beta-farnesene and isoprene, respectively, were probed with substrate analogs and kinetic measurements. The results support stepwise reaction mechanisms through analogous enzyme-bound allylic cationic intermediates. For EBFS, we demonstrate that the elimination reaction can proceed via the enzyme-bound intermediate trans-nerolidyl diphosphate, while for ISPS the intermediacy of 2-methylbut-3-enyl 2-diphosphate can be inferred from the product outcome when deuterated DMADPs are used as substrates. Possible implications derived from the mechanistic details of the EBFS-catalyzed reaction for the evolution of sesquiterpene synthases are discussed"
Keywords:		Alkyl and Aryl Transferases/*metabolism Butadienes/metabolism Hemiterpenes/metabolism Mentha/*metabolism Organophosphorus Compounds/metabolism Pentanes/metabolism Plant Proteins/*metabolism Polyisoprenyl Phosphates/metabolism Populus/*metabolism Pyrophosp;
Notes:		"MedlineFaraldos, Juan A Gonzalez, Veronica Li, Amang Yu, Fanglei Koksal, Mustafa Christianson, David W Allemann, Rudolf K eng R01 GM056838/GM/NIGMS NIH HHS/ BB/G003572/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom GM56838/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2012/12/12 J Am Chem Soc. 2012 Dec 26; 134(51):20844-8. doi: 10.1021/ja311022s. Epub 2012 Dec 11"