Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Plant Cell
2006 Dec 01;1812:3656-69. doi: 10.1105/tpc.106.041376.
Show Gene links
Show Anatomy links
Structural basis for dual functionality of isoflavonoid O-methyltransferases in the evolution of plant defense responses.
Liu CJ
,
Deavours BE
,
Richard SB
,
Ferrer JL
,
Blount JW
,
Huhman D
,
Dixon RA
,
Noel JP
.
???displayArticle.abstract???
In leguminous plants such as pea (Pisum sativum), alfalfa (Medicago sativa), barrel medic (Medicago truncatula), and chickpea (Cicer arietinum), 4''-O-methylation of isoflavonoid natural products occurs early in the biosynthesis of defense chemicals known as phytoalexins. However, among these four species, only pea catalyzes 3-O-methylation that converts the pterocarpanoid isoflavonoid 6a-hydroxymaackiain to pisatin. In pea, pisatin is important for chemical resistance to the pathogenic fungus Nectria hematococca. While barrel medic does not biosynthesize 6a-hydroxymaackiain, when cell suspension cultures are fed 6a-hydroxymaackiain, they accumulate pisatin. In vitro, hydroxyisoflavanone 4''-O-methyltransferase (HI4''OMT) from barrel medic exhibits nearly identical steady state kinetic parameters for the 4''-O-methylation of the isoflavonoid intermediate 2,7,4''-trihydroxyisoflavanone and for the 3-O-methylation of the 6a-hydroxymaackiain isoflavonoid-derived pterocarpanoid intermediate found in pea. Protein x-ray crystal structures of HI4''OMT substrate complexes revealed identically bound conformations for the 2S,3R-stereoisomer of 2,7,4''-trihydroxyisoflavanone and the 6aR,11aR-stereoisomer of 6a-hydroxymaackiain. These results suggest how similar conformations intrinsic to seemingly distinct chemical substrates allowed leguminous plants to use homologous enzymes for two different biosynthetic reactions. The three-dimensional similarity of natural small molecules represents one explanation for how plants may rapidly recruit enzymes for new biosynthetic reactions in response to changing physiological and ecological pressures.
Akashi,
cDNA cloning and biochemical characterization of S-adenosyl-L-methionine: 2,7,4'-trihydroxyisoflavanone 4'-O-methyltransferase, a critical enzyme of the legume isoflavonoid phytoalexin pathway.
2003, Pubmed
Akashi,
cDNA cloning and biochemical characterization of S-adenosyl-L-methionine: 2,7,4'-trihydroxyisoflavanone 4'-O-methyltransferase, a critical enzyme of the legume isoflavonoid phytoalexin pathway.
2003,
Pubmed
Akashi,
Cloning and functional expression of a cytochrome P450 cDNA encoding 2-hydroxyisoflavanone synthase involved in biosynthesis of the isoflavonoid skeleton in licorice.
1999,
Pubmed
Akashi,
New scheme of the biosynthesis of formononetin involving 2,7,4'-trihydroxyisoflavanone but not daidzein as the methyl acceptor.
2000,
Pubmed
Akashi,
Molecular and biochemical characterization of 2-hydroxyisoflavanone dehydratase. Involvement of carboxylesterase-like proteins in leguminous isoflavone biosynthesis.
2005,
Pubmed
Bradford,
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.
1976,
Pubmed
Brünger,
Crystallography & NMR system: A new software suite for macromolecular structure determination.
1998,
Pubmed
Doublié,
Preparation of selenomethionyl proteins for phase determination.
1997,
Pubmed
Hashim,
Reaction mechanism of oxidative rearrangement of flavanone in isoflavone biosynthesis.
1990,
Pubmed
He,
Stress responses in alfalfa (Medicago sativa L). XXII. cDNA cloning and characterization of an elicitor-inducible isoflavone 7-O-methyltransferase.
1998,
Pubmed
He,
Affinity chromatography, substrate/product specificity, and amino acid sequence analysis of an isoflavone O-methyltransferase from alfalfa (Medicago sativa L.).
1996,
Pubmed
Hendricks,
An enzyme-coupled colorimetric assay for S-adenosylmethionine-dependent methyltransferases.
2004,
Pubmed
Jones,
Improved methods for building protein models in electron density maps and the location of errors in these models.
1991,
Pubmed
Kochs,
Enzymic synthesis of isoflavones.
1986,
Pubmed
Kumar,
MEGA3: Integrated software for Molecular Evolutionary Genetics Analysis and sequence alignment.
2004,
Pubmed
Liu,
Regiospecific hydroxylation of isoflavones by cytochrome p450 81E enzymes from Medicago truncatula.
2003,
Pubmed
Liu,
Elicitor-induced association of isoflavone O-methyltransferase with endomembranes prevents the formation and 7-O-methylation of daidzein during isoflavonoid phytoalexin biosynthesis.
2001,
Pubmed
Matthews,
Role of oxygenases in pisatin biosynthesis and in the fungal degradation of maackiain.
1987,
Pubmed
,
Echinobase
O'Brien,
Catalytic promiscuity and the evolution of new enzymatic activities.
1999,
Pubmed
Otwinowski,
Processing of X-ray diffraction data collected in oscillation mode.
1997,
Pubmed
Pichersky,
Genetics and biochemistry of secondary metabolites in plants: an evolutionary perspective.
2000,
Pubmed
Preisig,
Purification and Characterization of S-Adenosyl-l-methionine:6a-Hydroxymaackiain 3-O-Methyltransferase from Pisum sativum.
1989,
Pubmed
Preisig,
Induction of 6a-hydroxymaackiain 3-O-methyltransferase and phenylalanine ammonia-lyase mRNA translational activities during the biosynthesis of pisatin.
1991,
Pubmed
Sawada,
Key amino acid residues required for aryl migration catalysed by the cytochrome P450 2-hydroxyisoflavanone synthase.
2002,
Pubmed
Suzuki,
Methyl jasmonate and yeast elicitor induce differential transcriptional and metabolic re-programming in cell suspension cultures of the model legume Medicago truncatula.
2005,
Pubmed
Terwilliger,
Automated MAD and MIR structure solution.
1999,
Pubmed
Terwilliger,
Reciprocal-space solvent flattening.
1999,
Pubmed
Thompson,
CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.
1994,
Pubmed
Wengenmayer,
Purification and properties of a S-adenosylmethionine: isoflavone 4'-O-methyltransferase from cell suspension cultures of Cicer arietinum L.
1974,
Pubmed
Wu,
Isolation of the cDNAs encoding (+)6a-hydroxymaackiain 3-O-methyltransferase, the terminal step for the synthesis of the phytoalexin pisatin in Pisum sativum.
1997,
Pubmed
,
Echinobase
Wu,
Introduction of plant and fungal genes into pea (Pisum sativum L.) hairy roots reduces their ability to produce pisatin and affects their response to a fungal pathogen.
2004,
Pubmed
,
Echinobase
Zubieta,
Structures of two natural product methyltransferases reveal the basis for substrate specificity in plant O-methyltransferases.
2001,
Pubmed
Zubieta,
Structural basis for the modulation of lignin monomer methylation by caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase.
2002,
Pubmed
