title: Biochemical and molecular characterization of a quercetinase from Penicillium olsonii.
abstract: Quercetinase (quercetin 2,3-dioxygenase, EC 1.13.11.24) is produced by various filamentous fungi when grown on rutin as the sole carbon and energy source. From a rutin based liquid culture of Penicillium olsonii, we purified a quercetinase with a specific activity of 175U mg(-1). The enzyme is a monomeric glycoprotein of approximately 55 kDa, containing 0.9+/-0.1 copper atoms per protein. Its substrate specificity is restricted to the flavonol family of flavonoids. It is completely inhibited by diethyldithiocarbamate at a concentration of 100 nM and 1H-2-benzyl-3-hydroxy-4-oxoquinolin is a competitive inhibitor with a K(I) of 4 microM. The cDNA poquer1 was cloned and sequenced. It encodes a 365 amino acids long enzyme with a strong sequence identity with the Aspergillus japonicus quercetinase (Q7SIC2). Like the enzyme from A. japonicus, only one of the two cupin domains of the Penicillium olsonii quercetinase is able to bind a metal atom.
authors.affiliation: Laboratoire BiosCiences FRE CNRS 3005, case 432, Faculté des Sciences et Techniques de Saint Jérôme, Aix-Marseille Université, avenue Escadrille Normandie-Niemen, 133397 Marseille Cedex 20, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Tranchimand
authors.forename: Gisela
authors.initials: G
authors.lastname: Ertel
authors.forename: Vincent
authors.initials: V
authors.lastname: Gaydou
authors.forename: Christian
authors.initials: C
authors.lastname: Gaudin
authors.forename: Thierry
authors.initials: T
authors.lastname: Tron
authors.forename: Gilles
authors.initials: G
authors.lastname: Iacazio
mesh_terms: D000595:Amino Acid Sequence; D018076:DNA, Complementary; D049308:Dioxygenases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010407:Penicillium / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D049308:Dioxygenases; C003281:quercetin 2,3-dioxygenase