title: An aryl dioxygenase shows remarkable double dioxygenation capacity for diverse bis-aryl compounds, provided they are carbocyclic.
abstract: The bacterial dioxygenation of mono- or polycyclic aromatic compounds is an intensely studied field. However, only in a few cases has the repeated dioxygenation of a substrate possessing more than a single aromatic ring been described. We previously characterized the aryl-hydroxylating dioxygenase BphA-B4h, an artificial hybrid of the dioxygenases of the biphenyl degraders Burkholderia xenovorans LB400 and Pseudomonas sp. strain B4-Magdeburg, which contains the active site of the latter enzyme, as an exceptionally powerful biocatalyst. We now show that this dioxygenase possesses a remarkable capacity for the double dioxygenation of various bicyclic aromatic compounds, provided that they are carbocyclic. Two groups of biphenyl analogues were examined: series A compounds containing one heterocyclic aromatic ring and series B compounds containing two homocyclic aromatic rings. Whereas all of the seven partially heterocyclic biphenyl analogues were solely dioxygenated in the homocyclic ring, four of the six carbocyclic bis-aryls were converted into ortho,meta-hydroxylated bis-dihydrodiols. Potential reasons for failure of heterocyclic dioxygenations are discussed. The obtained bis-dihydrodiols may, as we also show here, be enzymatically re-aromatized to yield the corresponding tetraphenols. This opens a way to a range of new polyphenolic products, a class of compounds known to exert multiple biological activities. Several of the obtained compounds are novel molecules.
authors.affiliation: Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, D-38124, Braunschweig, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Overwin
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center for Nanotechnology and Systems Biology & Centro de Biotecnología, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Myriam
authors.initials: M
authors.lastname: González
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center for Nanotechnology and Systems Biology & Centro de Biotecnología, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Valentina
authors.initials: V
authors.lastname: Méndez
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center for Nanotechnology and Systems Biology & Centro de Biotecnología, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Michael
authors.initials: M
authors.lastname: Seeger
authors.affiliation: Department of Molecular Structural Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Victor
authors.initials: V
authors.lastname: Wray
authors.affiliation: Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, D-38124, Braunschweig, Germany. bernd.hofer@helmholtz-hzi.de.|Division of Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany. bernd.hofer@helmholtz-hzi.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hofer
mesh_terms: D002264:Carboxylic Acids / Q000378:metabolism*; D049308:Dioxygenases / Q000378:metabolism*; D006844:Hydrocarbons, Cyclic / Q000378:metabolism*; D010084:Oxidation-Reduction; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D002264:Carboxylic Acids; D006844:Hydrocarbons, Cyclic; D011993:Recombinant Fusion Proteins; D049308:Dioxygenases
keywords: Dehydrogenation; Dihydrodiol; Dioxygenation; Heteroaryl; Homoaryl; Polyphenol