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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-12-13
pubmed:databankReference
pubmed:abstractText
In the flowers of important ornamental Compositae plants, anthocyanins generally carry malonyl group(s) at their 3-glucosyl moiety. In this study, for the first time to our knowledge, we have identified a cDNA coding for this 3-glucoside-specific malonyltransferase for anthocyanins, i.e. malonyl-coenzyme A:anthocyanidin 3-O-glucoside-6"-O-malonyltransferase, from dahlia (Dahlia variabilis) flowers. We isolated a full-length cDNA (Dv3MaT) on the basis of amino acid sequences specifically conserved among anthocyanin acyltransferases of the versatile plant acyltransferase family. Dv3MaT coded for a protein of 460 amino acids. Quantitative real-time PCR analyses of Dv3MaT showed that the transcript was present in accordance with the distribution of 3MaT activities and the anthocyanin accumulation pattern in the dahlia plant. The Dv3MaT cDNA was expressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity and characterized. The recombinant Dv3MaT catalyzed the regiospecific transfer of the malonyl group from malonyl-coenzyme A (K(m), 18.8 microM) to pelargonidin 3-O-glucoside (K(m), 46.7 microM) to produce pelargonidin 3-O-6"-O-malonylglucoside with a k(cat) value of 7.3 s(-1). The other enzymatic profiles of the recombinant Dv3MaT were closely related to those of native anthocyanin malonyltransferase activity in the extracts of dahlia flowers. Dv3MaT cDNA was introduced into petunia (Petunia hybrida) plants whose red floral color is exclusively provided by cyanidin 3-O-glucoside and 3,5-O-diglucoside. Thirteen transgenic lines of petunia were found to produce malonylated products of these anthocyanins (11-63 mol % of total anthocyanins in the flower). The spectral stability of cyanidin 3-O-6"-O-malonylglucoside at the pHs of intracellular milieus of flowers was significantly higher than that of cyanidin 3-O-glucoside. Moreover, 6"-O-malonylation of cyanidin 3-O-glucoside effectively prevented the anthocyanin from attack of beta-glucosidase. These results suggest that malonylation should serve as a strategy for pigment stabilization in the flowers.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-10639122, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-10666320, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-10712525, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-10845463, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-11095755, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-11404355, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-11598135, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-1368724, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-8720924, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-9426598, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-9628024, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-9681034, http://linkedlifedata.com/resource/pubmed/commentcorrection/12481098-9881162
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2142-51
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed-meshheading:12481098-Acyltransferases, pubmed-meshheading:12481098-Amino Acid Sequence, pubmed-meshheading:12481098-Anthocyanins, pubmed-meshheading:12481098-Cloning, Molecular, pubmed-meshheading:12481098-DNA, Complementary, pubmed-meshheading:12481098-Dahlia, pubmed-meshheading:12481098-Escherichia coli, pubmed-meshheading:12481098-Flowers, pubmed-meshheading:12481098-Gene Expression Regulation, Enzymologic, pubmed-meshheading:12481098-Gene Expression Regulation, Plant, pubmed-meshheading:12481098-Molecular Sequence Data, pubmed-meshheading:12481098-Petunia, pubmed-meshheading:12481098-Plants, Genetically Modified, pubmed-meshheading:12481098-Polymerase Chain Reaction, pubmed-meshheading:12481098-Sequence Analysis, DNA, pubmed-meshheading:12481098-Sequence Homology, Amino Acid, pubmed-meshheading:12481098-Substrate Specificity
pubmed:year
2002
pubmed:articleTitle
cDNA cloning, heterologous expressions, and functional characterization of malonyl-coenzyme a:anthocyanidin 3-o-glucoside-6"-o-malonyltransferase from dahlia flowers.
pubmed:affiliation
Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba-yama 07, Sendai 980-8579, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't