|
KMID : 0368420060490010055
|
|
Journal of Plant Biology
2006 Volume.49 No. 1 p.55 ~ p.60
|
|
|
Caffeic acid o-methyltransferase fromPopulus deltoides: functional expression and characterization
|
|
Kim Bong-Gyu
Lee Yoon-Jung
Park Young-Hee
Lim Yoong-Ho
Ahn Joong-Hoon
|
|
|
Abstract
|
|
|
|
Enzymatic O-methylation, catalyzed by S-adenosyl-L-methionine (SAM)-dependent O-methyltranferases (OMTs), is a ubiquitous reaction, occurring in almost all living organisms. Plant OMTs are involved in the methylation of secondary metabolites, including phenylpropanoid and flavonoid compounds. Here, we used RT-PCR to isolate and characterizePOMT-2 fromPopulus deltoides. This OMT comprises a 1095-b open reading frame that encodes a 39.7-kDa protein. BLAST results showed 87% identities to an OMT fromPrunus dulcis and a caffeic acid OMT fromRosa chinensis. POMT-2 was expressed inEscherichia coli as a glutathione S-transferase fusion protein, and was purified by affinity chromatography. POMT-2 transferred a methyl group of SAM to caffeic acid and 6,7-dihydroxyflavone, but showed low activities toward quercetin and kaempferol. According to itsin vitro substrate preference and composition of phenolic compounds in poplar, thein vivo function of POMT-2 is probably the methylation of caffeic acid and an involvement in lignin biosynthesis.
|
|
|
KEYWORD
|
|
|
caffeic acid, flavonoids, O-methyltransferase
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|