title: Amorpha-4,11-diene synthase: cloning and functional expression of a key enzyme in the biosynthetic pathway of the novel antimalarial drug artemisinin.
abstract: The sesquiterpenoid artemisinin, isolated these from the plant Artemisia annua L., and its semi-synthetic derivatives are a new and very effective group of antimalarial drugs. A branch point in the biosynthesis of this compound is the cyclisation of the ubiquitous precursor farnesyl diphosphate into the first specific precursor of artemisinin, namely amorpha-4,11-diene. Here we describe the isolation of a cDNA clone encoding amorpha-4,11-diene synthase. The deduced amino acid sequence exhibits the highest identity (50%) with a putative sesquiterpene cyclase of A. annua. When expressed in Escherichia coli, the recombinant enzyme catalyses the formation of amorpha-4,11-diene from farnesyl diphosphate. Introduction of the gene into tobacco (Nicotiana tabacum L.) resulted in the expression of an active enzyme and the accumulation of amorpha-4,11-diene ranging from 0.2 to 1.7 ng per g fresh weight.
authors: GenoClipp Biotechnology BV, Meditech Center, Groningen, The Netherlands. mail@genoclipp.com
authors: T E
authors: TE
authors: Wallaart
authors: H J
authors: HJ
authors: Bouwmeester
authors: J
authors: J
authors: Hille
authors: L
authors: L
authors: Poppinga
authors: N C
authors: NC
authors: Maijers
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000962:Antimalarials / Q000302:isolation & purification; D019306:Artemisia / Q000737:chemistry / Q000235:genetics; D037621:Artemisinins; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D015870:Gene Expression; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D010947:Plants, Toxic; D016133:Polymerase Chain Reaction; D012313:RNA / Q000302:isolation & purification; D012717:Sesquiterpenes / Q000302:isolation & purification; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D018076:DNA, Complementary; D012717:Sesquiterpenes; D012313:RNA; C031327:artemisinin; D019883:Alkyl and Aryl Transferases; C403714:amorpha-4,11-diene synthase