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Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Characterization of flavone synthase I from rice
Yoon Jung Lee1, Jeong Ho Kim, Bong Gyu Kim
1Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea.
BMB Reports
|February 29, 2008
Summary
Rice flavone synthase I (OsFNS I-1) converts flavanone to apigenin. This study identifies the first flavone synthase I enzyme outside the Apiaceae family, expanding our understanding of flavone biosynthesis.
Area of Science:
- Biochemistry
- Plant Science
- Molecular Biology
Background:
- Flavonoids, including flavones, are crucial plant secondary metabolites with diverse biological activities.
- Flavone biosynthesis occurs via flavanone synthases (FNSs), with FNS I and FNS II being the known types.
- FNS I is typically found in Apiaceae, while FNS II is a cytochrome P450 enzyme present in many species.
Purpose of the Study:
- To clone, express, and characterize the flavone synthase I gene from rice (Oryza sativa).
- To determine the enzymatic activity and cofactor requirements of the rice FNS I enzyme.
- To investigate the presence of FNS I outside the Apiaceae family.
Main Methods:
- OsFNS I-1 gene isolated from rice using RT-PCR.
- Recombinant protein expressed and purified from E. coli.
- Enzymatic activity confirmed using NMR analysis, identifying substrate and product.
- Cofactor requirements determined through biochemical assays.
Main Results:
- The cloned rice gene, OsFNS I-1, encodes a functional flavone synthase I.
- OsFNS I-1 successfully converted (2S)-naringenin (flavanone) to apigenin (flavone).
- Essential cofactors identified: oxoglutarate, FeSO(4), ascorbate, and catalase.
- This represents the first identification of a type I FNS I in a plant species outside the Apiaceae family.
Conclusions:
- OsFNS I-1 is a functional flavone synthase I enzyme.
- The discovery of OsFNS I-1 in rice broadens the known distribution of FNS I enzymes.
- This finding contributes to a deeper understanding of the evolution and diversity of flavone biosynthesis pathways in plants.
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