title: Molecular characterization of flavonol synthase from poplar and its application to the synthesis of 3-O-methylkaempferol.
abstract: Biosynthesis of flavonoid derivatives requires enzyme(s) having high reactivity as well as regioselectivity. We have synthesized 3-O-kaempferol from naringenin using two enzymes. The first reaction, in which naringenin is converted to kaempferol, is mediated by flavonol synthase (FLS). An FLS (PFLS) with strong catalytic activity was cloned and characterized from the genome sequence of the poplar (Populus deltoides). PFLS consists of a 1,008 bp ORF encoding a 38 kDa protein. PFLS was expressed in Escherichia coli with a glutathione-S-transferase (GST) tagging. The purified recombinant PFLS was characterized. Catalytically, it was more efficient than the previously characterized FLSs. A mixture of two E. coli transformants harboring either PFLS or ROMT9 (a kaempferol 3-O-methyltransferase) converted naringenin into 3-O-methylkaempferol.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-901, Korea.
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Kim
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Joe
authors.forename: Joong-Hoon
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000235:genetics; D044950:Flavanones / Q000378:metabolism; D044949:Kaempferols / Q000096:biosynthesis*; D007700:Kinetics; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D032107:Populus / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D053719:Tandem Mass Spectrometry
chemical_list: C464826:3-methylkaempferol; D044950:Flavanones; D044949:Kaempferols; D010940:Plant Proteins; D011994:Recombinant Proteins; D010088:Oxidoreductases; C085313:flavonol synthase; D008780:Methyltransferases; C005273:naringenin