A new group of aromatic prenyltransferases in fungi, catalyzing a 2,7-dihydroxynaphthalene 3-dimethylallyl-transferase reaction.
Five fungal genomes from the Ascomycota (sac fungi) were found to contain a gene with sequence similarity to a recently discovered small group of bacterial prenyltransferases that catalyze the C-prenylation of aromatic substrates in secondary metabolism. The genes from Aspergillus terreus NIH2624, Botryotinia fuckeliana B05.10 and Sclerotinia sclerotiorum 1980 were expressed in Escherichia coli, and the resulting His(8)-tagged proteins were purified and investigated biochemically. Their substrate specificity was found to be different from that of any other prenyltransferase investigated previously. Using 2,7-dihydroxynaphthalene (2,7-DHN) and dimethylallyl diphosphate as substrates, they catalyzed a regiospecific Friedel-Crafts alkylation of 2,7-DHN at position 3. Using the enzyme of A. terreus, the K(m) values for 2,7-DHN and dimethylallyl diphosphate were determined as 324 +/- 25 microM and 325 +/- 35 microM, respectively, and k(cat) as 0.026 +/- 0.001 s(-1). A significantly lower level of prenylation activity was found using dihydrophenazine-1-carboxylic acid as aromatic substrate, and only traces of products were detected with aspulvinone E, flaviolin, or 4-hydroxybenzoic acid. No product was formed with l-tryptophan, l-tyrosine, or 4-hydroxyphenylpyruvate. The genes for these fungal prenyltransferases are not located within recognizable secondary metabolic gene clusters. Their physiological function is yet unknown.
Haug-Schifferdecker
Elisa
E
Pharmazeutische Biologie, Pharmazeutisches Institut, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany.
Arican
Deniz
D
Brückner
Reinhard
R
Heide
Lutz
L
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology; D001230:Aspergillus / Q000201:enzymology; D001671:Biochemistry / Q000379:methods; D004122:Dimethylallyltranstransferase / Q000737:chemistry* / Q000235:genetics; D005658:Fungi / Q000201:enzymology; D045782:Hemiterpenes / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008969:Molecular Sequence Data; D005810:Multigene Family; D009284:Naphthols / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D045782:Hemiterpenes; D009284:Naphthols; D009943:Organophosphorus Compounds; C107946:2,7-dihydroxynaphthalene; C043060:3,3-dimethylallyl pyrophosphate; D004122:Dimethylallyltranstransferase