title: Cloning, expression, and sequence analysis of the three genes encoding quinoline 2-oxidoreductase, a molybdenum-containing hydroxylase from Pseudomonas putida 86.
abstract: The three genes coding for quinoline 2-oxidoreductase (Qor) of Pseudomonas putida 86 were cloned and sequenced. The qor genes are clustered in the transcriptional order medium (M) small (S), large (L) and code for three subunits of 288 (QorM), 168 (QorS), and 788 (QorL) amino acids, respectively. Formation of active quinoline 2-oxidoreductase and degradation of quinoline occurred in a recombinant P. putida KT2440 clone. The amino acid sequences of Qor show significant homology to various prokaryotic molybdenum containing hydroxylases and to eukaryotic xanthine dehydrogenases. QorS contains two conserved motifs for [2Fe-2S] clusters. The binding motif for the N-terminal [2Fe-2S] cluster corresponds to the binding site of bacterial and chloroplast-type [2Fe-2S] ferredoxins, whereas the amino acid pattern of the internal [2Fe-2S] center apparently is a distinct feature of molybdenum-containing hydroxylases, showing no homology to any other described [2Fe-2S] binding motif. The medium subunit QorM presumably contains the FAD, but no conserved sequence areas or described motifs of FAD, NAD, NADP, or ATP binding were detected. Putative binding sites of the molybdopterin cytosine dinucleotide cofactor were detected in QorL by comparison with "contacting segments" recently described in aldehyde oxidoreductase from Desulfovibrio gigas (Romão, M. J., Archer, M., Moura, I., Moura, J. J. G., LeGall, J., Engh, R., Schneider, M., Hof, P., and Huber, R. (1995) Science 270, 1170-1176).
authors.affiliation: Institut für Mikrobiologie (250), Universität Hohenheim, D-70593 Stuttgart, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bläse
authors.forename: C
authors.initials: C
authors.lastname: Bruntner
authors.forename: B
authors.initials: B
authors.lastname: Tshisuaka
authors.forename: S
authors.initials: S
authors.lastname: Fetzner
authors.forename: F
authors.initials: F
authors.lastname: Lingens
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D008982:Molybdenum / Q000032:analysis*; D010088:Oxidoreductases / Q000096:biosynthesis / Q000235:genetics*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D016958:Pseudomonas putida / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis; D016415:Sequence Alignment / Q000379:methods; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D008982:Molybdenum; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C068667:quinoline 2-oxidoreductase