Plant Physiology Preview
Published on February 25, 2005; 10.1104/pp.104.056747
Received November 22, 2004
Returned for revision December 17, 2004
Accepted December 20, 2004
Molecular and Biochemical Characterization of 2-Hydroxyisoflavanone Dehydratase. Involvement of Carboxylesterase-Like Proteins in Leguminous Isoflavone Biosynthesis
Tomoyoshi Akashi , Toshio Aoki , and Shin-ichi Ayabe *
Department of Applied Biological Sciences, Nihon University, Fujisawa, Kanagawa 252-8510, Japan
* Corresponding author; email: ayabe{at}brs.nihon-u.ac.jp.
Isoflavonoids are ecophysiologically active secondary metabolites of the Leguminosae and known for health-promoting phytoestrogenic functions. Isoflavones are synthesized by 1,2-elimination of water from 2-hydroxyisoflavanones, the first intermediate with the isoflavonoid skeleton, but details of this dehydration have been unclear. We screened the extracts of repeatedly fractionated Escherichia coli expressing a Glycyrrhiza echinata cDNA library for the activity to convert a radiolabeled precursor into formononetin (7-hydroxy-4'-methoxyisoflavone), and a clone of 2-hydroxyisoflavanone dehydratase (HID) was isolated. Another HID cDNA was cloned from soybean (Glycine max), based on the sequence information in its expressed sequence tag library. Kinetic studies revealed that G. echinata HID is specific to 2,7-dihydroxy-4'-methoxyisoflavanone, while soybean HID has broader specificity to both 4'-hydroxylated and 4'-methoxylated 2-hydroxyisoflavanones, reflecting the structures of isoflavones contained in each plant species. Strikingly, HID proteins were members of a large carboxylesterase family, of which plant proteins form a monophyletic group and some are assigned defensive functions with no intrinsic catalytic activities identified. Site-directed mutagenesis with soybean HID protein suggested that the characteristic oxyanion hole and catalytic triad are essential for the dehydratase as well as the faint esterase activities. The findings, to our knowledge, represent a new example of recruitment of enzymes of primary metabolism during the molecular evolution of plant secondary metabolism.
This article has been cited by other articles:
|
|
|
|
 
T. Akashi, K. Sasaki, T. Aoki, S.-i. Ayabe, and K. Yazaki
Molecular Cloning and Characterization of a cDNA for Pterocarpan 4-Dimethylallyltransferase Catalyzing the Key Prenylation Step in the Biosynthesis of Glyceollin, a Soybean Phytoalexin
Plant Physiology,
February 1, 2009;
149(2):
683 - 693.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. A. Farag, D. V. Huhman, R. A. Dixon, and L. W. Sumner
Metabolomics Reveals Novel Pathways and Differential Mechanistic and Elicitor-Specific Responses in Phenylpropanoid and Isoflavonoid Biosynthesis in Medicago truncatula Cell Cultures
Plant Physiology,
February 1, 2008;
146(2):
387 - 402.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Naoumkina, M. A. Farag, L. W. Sumner, Y. Tang, C.-J. Liu, and R. A. Dixon
Inaugural Article: Different mechanisms for phytoalexin induction by pathogen and wound signals in Medicago truncatula
PNAS,
November 13, 2007;
104(46):
17909 - 17915.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Shimamura, T. Akashi, N. Sakurai, H. Suzuki, K. Saito, D. Shibata, S.-i. Ayabe, and T. Aoki
2-Hydroxyisoflavanone Dehydratase is a Critical Determinant of Isoflavone Productivity in Hairy Root Cultures of Lotus japonicus
Plant Cell Physiol.,
November 1, 2007;
48(11):
1652 - 1657.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Noguchi, A. Saito, Y. Homma, M. Nakao, N. Sasaki, T. Nishino, S. Takahashi, and T. Nakayama
A UDP-Glucose:Isoflavone 7-O-Glucosyltransferase from the Roots of Soybean (Glycine max) Seedlings: PURIFICATION, GENE CLONING, PHYLOGENETICS, AND AN IMPLICATION FOR AN ALTERNATIVE STRATEGY OF ENZYME CATALYSIS
J. Biol. Chem.,
August 10, 2007;
282(32):
23581 - 23590.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. C. Gershater, I. Cummins, and R. Edwards
Role of a Carboxylesterase in Herbicide Bioactivation in Arabidopsis thaliana
J. Biol. Chem.,
July 20, 2007;
282(29):
21460 - 21466.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. Shimada, S. Sato, T. Akashi, Y. Nakamura, S. Tabata, S.-i. Ayabe, and T. Aoki
Genome-wide Analyses of the Structural Gene Families Involved in the Legume-specific 5-Deoxyisoflavonoid Biosynthesis of Lotus japonicus
DNA Res,
April 23, 2007;
(2007)
dsm004v1.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C.-J. Liu, B. E. Deavours, S. B. Richard, J.-L. Ferrer, J. W. Blount, D. Huhman, R. A. Dixon, and J. P. Noel
Structural Basis for Dual Functionality of Isoflavonoid O-Methyltransferases in the Evolution of Plant Defense Responses
PLANT CELL,
December 1, 2006;
18(12):
3656 - 3669.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. E. Deavours and R. A. Dixon
Metabolic Engineering of Isoflavonoid Biosynthesis in Alfalfa
Plant Physiology,
August 1, 2005;
138(4):
2245 - 2259.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
