title: Identification of a product specific beta-amyrin synthase from Arabidopsis thaliana.
abstract: Triterpene skeletons are produced by oxidosqualene cyclases (OSCs). The genome sequencing of Arabidopsis thaliana revealed the presence of thirteen OSC homologous genes including At1g78950, which has been revised recently as two independent ORFs, namely At1g78950 and At1g78955. The cDNA corresponding to the revised At1g78950 was obtained by RT-PCR, ligated into Saccharomyces cerevisiae expression vector pYES2, and expressed in a lanosterol synthase deficient S. cerevisiae strain. LC-MS and NMR analyses of the accumulated product in the host cells showed that the product of At1g78950 is beta-amyrin, indicating that At1g78950 encodes a beta-amyrin synthase (EC 5.4.99.-).
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shibuya
authors.forename: Yuji
authors.initials: Y
authors.lastname: Katsube
authors.forename: Miyuki
authors.initials: M
authors.lastname: Otsuka
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Pimpimon
authors.initials: P
authors.lastname: Tansakul
authors.forename: Ting
authors.initials: T
authors.lastname: Xiang
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ebizuka
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D018076:DNA, Complementary; D019143:Evolution, Molecular; D019751:Intramolecular Transferases / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D009828:Oleanolic Acid / Q000031:analogs & derivatives / Q000096:biosynthesis; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D014315:Triterpenes / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D014315:Triterpenes; D009828:Oleanolic Acid; D019751:Intramolecular Transferases; C039924:2,3-oxidosqualene-beta-amyrin-cyclase; C036380:beta-amyrin