title: Functional expression of a P450 flavonoid hydroxylase for the biosynthesis of plant-specific hydroxylated flavonols in Escherichia coli.
abstract: Flavonols are plant polyphenolic compounds that belong to the class of molecules collectively known as flavonoids. Because of their demonstrated health benefits towards a wide array of human pathological conditions, a great interest has emerged for their biosynthesis from well-characterized microbial hosts. We present the functional expression in Escherichia coli of a plant P450 flavonoid 3', 5'-hydroxylase (F3'5'H) as a fusion protein with a P450 reductase. This expression allowed metabolic engineering of E. coli to produce the flavonol kaempferol and the 3', 4' B-ring hydroxylated flavonol quercetin from the p-coumaric acid precursor by simultaneously co-expressing the fusion protein with 4-coumaroyl:CoA-ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3beta-hydroxylase (FHT) and flavonol synthase (FLS). Biosynthesis of the B-ring tri-hydroxylated flavonol myricetin from the engineered strains was accomplished when flavanones rather than phenylpropanoid acids were used as precursor molecules. Cultivation of the recombinant strains in rich medium increased the synthesis of all flavonoids with the exception of myricetin. The present work opens the possibility of the future production of several other hydroxylated flavonoid molecules in E. coli.
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo, the State University of New York, 904 Furnas Hall, NY 14260, USA.
authors.forename: Effendi
authors.initials: E
authors.lastname: Leonard
authors.forename: Yajun
authors.initials: Y
authors.lastname: Yan
authors.forename: Mattheos A G
authors.initials: MA
authors.lastname: Koffas
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D044948:Flavonols / Q000096:biosynthesis* / Q000235:genetics; D019684:Magnoliopsida / Q000235:genetics* / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis
chemical_list: D044948:Flavonols; D011993:Recombinant Fusion Proteins; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C038888:flavonoid 3'-hydroxylase; D009251:NADPH-Ferrihemoprotein Reductase