Identification of membrane-bound quinoprotein inositol dehydrogenase in Gluconobacter oxydans ATCC 621H.
The GOX1857 gene, which encodes a putative membrane-bound pyrroloquinoline quinone (PQQ)-dependent dehydrogenase in Gluconobacter oxydans ATCC 621H, was characterized. GOX1857 was disrupted and the oxidizing potential of the resulting mutant strain was compared to that of the wild-type. In contrast to the wild-type, the mutant was unable to grow with myo-inositol as the sole energy source and did not show any myo-inositol dehydrogenase activity in vitro, indicating that GOX1857 encodes an inositol dehydrogenase. The association of inositol dehydrogenase with the membrane and the requirement for the cofactor PQQ were confirmed. Inositol dehydrogenase exhibited optimal activity at pH 8.75. As indicated by cultivation on different substrates, inositol dehydrogenase was repressed by d-glucose.
Hölscher
Tina
T
Fachgebiet Technische Biochemie, Institut für Biotechnologie, Technische Universität Berlin, D-13353 Berlin, Germany. Tina.Hoelscher@TU-berlin.de
Weinert-Sepalage
Dinusha
D
Görisch
Helmut
H
D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000201:enzymology*; D015964:Gene Expression Regulation, Bacterial; D020600:Gluconobacter oxydans / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007294:Inositol / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D017422:Sequence Analysis, DNA
D007294:Inositol; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D005947:Glucose