title: Cloning, nucleotide sequence, and expression of the gene encoding a novel dioxygenase involved in metabolism of carboxydiphenyl ethers in Pseudomonas pseudoalcaligenes POB310.
abstract: Pseudomonas pseudoalcaligenes strain POB310 degrades 3- and 4-carboxydiphenyl ether. The initial reaction involves an angular dioxygenation yielding an unstable hemiacetal that spontaneously decays to phenol and protocatechuate. We cloned a DNA fragment containing the gene encoding the initial dioxygenase from an unstable, self-transmissible plasmid. Sequence analysis revealed two open reading frames encoding proteins with putative molecular masses of 46.3 and 33.6 kDa. The deduced amino acid sequences showed homologies to oxygenase and reductase subunits of aromatic ring-activating dioxygenases, and contained regions identical to consensus sequences that bind chloroplast-like and Rieske-type [2Fe2S] clusters, suggesting that the initial dioxygenase is a class IA aromatic ring-activating dioxygenase system. Initial dioxygenase activity was induced in bacteria grown in M9 minimal medium containing 3- or 4-carboxydiphenyl ether or phenol as carbon source, indicating that the regulation is dependent on the phenol pathway. The maximal specific activity was measured at the beginning of the exponential growth phase.
authors.affiliation: Department of Microbiology, G.B.F. National Research Center for Biotechnology, Braunschweig, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Dehmel
authors.forename: K H
authors.initials: KH
authors.lastname: Engesser
authors.forename: K N
authors.initials: KN
authors.lastname: Timmis
authors.forename: D F
authors.initials: DF
authors.lastname: Dwyer
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001565:Benzoates / Q000378:metabolism*; D002455:Cell Division; D003001:Cloning, Molecular; D004790:Enzyme Induction; D015870:Gene Expression; D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010101:Oxygen Consumption; D010647:Phenyl Ethers / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D001565:Benzoates; D010647:Phenyl Ethers; C065921:4-carboxybiphenyl ether; D006899:Mixed Function Oxygenases; C092910:PobB protein, Pseudomonas pseudoalcaligenes