title: Molecular cloning and biochemical characterization of two UDP-glycosyltransferases from poplar.
abstract: Two pathogen-induced uridine diphosphate glycosyltransferases (UGTs) identified previously via co-expression with induced proanthocyanidin (PA) synthesis in poplar were cloned and characterized. Phylogenetic analysis grouped both genes with other known flavonoid UGTs that act on flavonols and anthocyanins. Recombinant enzymes were produced in order to test if they could glycoslate flavonoids. PtUGT78L1 accepted the flavonols quercetin and kaempferol as well as cyanidin, and used UDP-galactose as a sugar donor. PtUGT78M1 did not accept any of the flavonoids tested as a substrate, but did transfer glucose from UDP-glucose to the universal substrate 2,4,6-trichlorophenol. However, neither enzyme acted on the flavan-3-ols catechin or epicatechin, intermediates in the PA biosynthetic pathway.
authors: Centre for Forest Biology and Department of Biology, University of Victoria, Victoria, BC, Canada.
authors: Vasko
authors: V
authors: Veljanovski
authors: C Peter
authors: CP
authors: Constabel
mesh_terms: D003001:Cloning, Molecular; D014453:Glucuronosyltransferase / Q000235:genetics* / Q000378:metabolism*; D008958:Models, Molecular; D015394:Molecular Structure; D032107:Populus / Q000201:enzymology*; D044945:Proanthocyanidins / Q000096:biosynthesis / Q000737:chemistry; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D044945:Proanthocyanidins; D011994:Recombinant Proteins; C013221:proanthocyanidin; D014453:Glucuronosyltransferase