Molecular characterization of flavonol synthase from poplar and its application to the synthesis of 3-O-methylkaempferol.
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.
Kim
Bong-Gyu
BG
Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-901, Korea.
Joe
Eun Ji
EJ
Ahn
Joong-Hoon
JH
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
C464826:3-methylkaempferol; D044950:Flavanones; D044949:Kaempferols; D010940:Plant Proteins; D011994:Recombinant Proteins; D010088:Oxidoreductases; C085313:flavonol synthase; D008780:Methyltransferases; C005273:naringenin