title: Characterization of flavone synthase I from rice.
abstract: Flavones are synthesized from flavanones through the action of flavone synthases (FNSs). There are two FNSs, FNS I and II. FNS I is a soluble dioxygenase present in members of the Apiaceae family and FNS II is a membrane bound cytochrome P450 enzyme that has been identified in numerous plant species. In this study, we cloned OsFNS I-1 from rice by RTPCR, expressed it in E. coli, and purified the recombinant protein. By NMR analysis, we found that OsFNS I-1 converted the flavanone (2S)-naringenin into the flavone, apigenin. Moreover, we found that the cofactors oxoglutarate, FeSO(4), ascorbate and catalase are required for this reaction. OsFNS I-1 encodes a flavone synthase I. This is the first type I FNS I found outside of the Apiaceae family.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea.
authors.forename: Yoon Jung
authors.initials: YJ
authors.lastname: Lee
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Kim
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: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004925:Escherichia / Q000235:genetics; D044950:Flavanones / Q000737:chemistry; D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000235:genetics*; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D044950:Flavanones; D006899:Mixed Function Oxygenases; C065998:flavone synthase I; C005273:naringenin