26770-40-1Relevant academic research and scientific papers
Identification of UGT84A13 as a candidate enzyme for the first committed step of gallotannin biosynthesis in pedunculate oak (Quercus robur)
Mittasch, Juliane,B?ttcher, Christoph,Frolova, Nadezhda,B?nn, Markus,Milkowski, Carsten
, p. 44 - 51 (2014)
A cDNA encoding the ester-forming hydroxybenzoic acid glucosyltransferase UGT84A13 was isolated from a cDNA library of Quercus robur swelling buds and young leaves. The enzyme displayed high sequence identity to resveratrol/hydroxycinnamate and hydroxybenzoate/hydroxycinnamate glucosyltransferases from Vitis species and clustered to the phylogenetic group L of plant glucosyltransferases, mainly involved in the formation of 1-O-β-d-glucose esters. In silico transcriptome analysis confirmed expression of UGT84A13 in Quercus tissues which were previously shown to exhibit UDP-glucose:gallic acid glucosyltransferase activity. UGT84A13 was functionally expressed in Escherichia coli as N-terminal His-tagged protein. In vitro kinetic measurements with the purified recombinant enzyme revealed a clear preference for hydroxybenzoic acids as glucosyl acceptor in comparison to hydroxycinnamic acids. Of the preferred in vitro substrates, protocatechuic, vanillic and gallic acid, only the latter and its corresponding 1-O-?-D-glucose ester were found to be accumulated in young oak leaves. This indicates that in planta UGT84A13 catalyzes the formation of, 1-O-galloyl-?-D-glucose, the first committed step of gallotannin biosynthesis.
