title: Flavanone 3beta-hydroxylases from rice: key enzymes for favonol and anthocyanin biosynthesis.
abstract: Flavanone 3beta-hydroxylases (F3H) are key enzymes in the synthesis of flavonol and anthocyanin. In this study, three F3H cDNAs from Oryza sativa (OsF3H-1 approximately 3) were cloned by RT-PCR and expressed in E. coli as gluthatione S-transferase (GST) fusion proteins. The purified recombinant OsF3Hs used flavanone, naringenin and eriodictyol as substrates. The reaction products with naringen and eriodictyol were determined by nuclear magnetic resonance spectroscopy to be dihydrokaempferol and taxifolin, respectively. OsF3H-1 had the highest enzymatic activity whereas the overall expression of OsF3H-2 was highest in all tissues except seeds. Flavanone 3beta-hydroxylase could be a useful target for flavonoid metabolic engineering in rice.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Yoon Jung
authors.initials: YJ
authors.lastname: Lee
authors.forename: Bong Gyu
authors.initials: BG
authors.lastname: Kim
authors.forename: Yoongho
authors.initials: Y
authors.lastname: Lim
authors.forename: Joong-Hoon
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000096:biosynthesis* / Q000737:chemistry; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D044948:Flavonols; D011994:Recombinant Proteins; D006899:Mixed Function Oxygenases; C048797:flavanone 3-dioxygenase