Biochemical and molecular characterization of a succinate semialdehyde dehydrogenase involved in the catabolism of 4-hydroxybutyric acid in Ralstonia eutropha.
A succinate semialdehyde dehydrogenase gene (gabD) was identified to be disrupted in a transposon-induced mutant of Ralstonia eutropha exhibiting the phenotype 4-hydroxybutyric acid-leaky. The native gabD gene was cloned by colony hybridization using a homologous gabD-specific DNA probe. DNA sequencing revealed an 1452-bp open reading frame, and the deduced amino acid sequence showed strong similarities to NADP(+)-dependent succinate semialdehyde dehydrogenases from Escherichia coli, Rhizobium sp., Homo sapiens and Rattus norvegicus. The gabD gene was heterologously expressed in a recombinant E. coli strain harboring plasmid pSK::EE6.8. Similar to the molecular organization of the gab cluster in E. coli, additional genes encoding enzymes for the degradation of gamma-aminobutyrate are closely related to gabD in R. eutropha. Enzymatic studies indicated the existence of a second NAD(+)-dependent succinate semialdehyde dehydrogenase in R. eutropha.
Lütke-Eversloh
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Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, D-48149, Münster, Germany.
Steinbüchel
A
A
D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D020118:Cupriavidus necator / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006885:Hydroxybutyrates / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D051381:Rats; D017422:Sequence Analysis, DNA; D050644:Succinate-Semialdehyde Dehydrogenase; D014169:Transformation, Bacterial
D004251:DNA Transposable Elements; D006885:Hydroxybutyrates; C111420:4-hydroxybutyric acid; D000445:Aldehyde Oxidoreductases; D050644:Succinate-Semialdehyde Dehydrogenase