Characterization of flavone synthase I from rice

  • Lee, Yoon-Jung (Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University) ;
  • Kim, Jeong-Ho (Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University) ;
  • Kim, Bong-Gyu (Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University) ;
  • Lim, Yoong-Ho (Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University) ;
  • Ahn, Joong-Hoon (Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University)
  • Published : 2008.01.31


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.


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