Biphenyl synthase from yeast-extract-treated cell cultures of Sorbus aucuparia.
Biphenyls and dibenzofurans are the phytoalexins of the Maloideae, a subfamily of the economically important Rosaceae. The biphenyl aucuparin accumulated in Sorbus aucuparia L. cell cultures in response to yeast extract treatment. Incubation of cell-free extracts from challenged cell cultures with benzoyl-CoA and malonyl-CoA led to the formation of 3,5-dihydroxybiphenyl. This reaction was catalysed by a novel polyketide synthase, which will be named biphenyl synthase. The most efficient starter substrate for the enzyme was benzoyl-CoA. Relatively high activity was also observed with 2-hydroxybenzoyl-CoA but, instead of the corresponding biphenyl, the derailment product 2-hydroxybenzoyltriacetic acid lactone was formed.
Liu
Benye
B
Institut für Pharmazeutische Biologie, Technische Universität Braunschweig, Mendelssohnstrasse 1, 38106 Braunschweig, Germany.
Beuerle
Till
T
Klundt
Tim
T
Beerhues
Ludger
L
D002474:Cell-Free System; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004229:Dithiothreitol / Q000494:pharmacology; D007700:Kinetics; D009097:Multienzyme Complexes / Q000302:isolation & purification / Q000378:metabolism*; D010940:Plant Proteins / Q000302:isolation & purification / Q000378:metabolism; D018514:Plant Structures / Q000201:enzymology; D031994:Sorbus / Q000166:cytology / Q000201:enzymology*; D013379:Substrate Specificity; D015003:Yeasts
D009097:Multienzyme Complexes; D010940:Plant Proteins; C482658:biphenyl synthase, Sorbus aucuparia; D004229:Dithiothreitol