Multiple regiospecific methylations of a flavonoid by plant O-methyltransferases expressed in E. coli.
Quercetin was methylated with two O-methyltransferases (OMTs) expressed in E. coli. A construct (RSOMT) was designed to express two OMTs: ROMT-9, which methylates specifically at the 3'-hydroxyl group of quercetin and SOMT-2, which methylates at the 4'-hydroxyl group. Both OMT genes were driven by T7 promoters and had ribosome binding sites. Both ROMT-9 and SOMT-2 were successfully expressed in E. coli transformant harboring RSOMT. Reaction products of quercetin with E. coli transformant containing RSOMT showed two methylation products that corresponded to the 3'-methylated and the 3',4'-dimethylated quercetin, which were confirmed by NMR. More than 90% of quercetin was converted into the 3',4'-dimethylated quercetin after 24 h incubation with E. coli transformant harboring RSOMT.
Kim
Bong Gyu
BG
Bio/Molecular Informatics Center, Department of Molecular Biotechnology, Konkuk University, 143-701, Seoul, Korea.
Shin
Kwang Hee
KH
Lee
Youngshim
Y
Hur
Hor-Gil
HG
Lim
Yoongho
Y
Ahn
Joong-Hoon
JH
D001711:Biotransformation; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000378:metabolism*; D044948:Flavonols / Q000096:biosynthesis / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D015394:Molecular Structure; D012275:Oryza / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011794:Quercetin / Q000031:analogs & derivatives / Q000378:metabolism; D014170:Transformation, Genetic / Q000235:genetics
D005419:Flavonoids; D044948:Flavonols; D010940:Plant Proteins; C047368:3-methylquercetin; D011794:Quercetin; D008780:Methyltransferases