Open AccessBiochemical and molecular characterization of a succinate semialdehyde dehydrogenase involved in the catabolism of 4‐hydroxybutyric acid in Ralstonia eutropha
Author(s) -
LütkeEversloh Tina,
Steinbüchel Alexander
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb08827.x
Subject(s) - ralstonia , escherichia coli , biology , biochemistry , gene , structural gene , plasmid , operon , microbiology and biotechnology , gene cluster , mutant , open reading frame , dehydrogenase , enzyme , peptide sequence
A succinate semialdehyde dehydrogenase gene ( gab D) was identified to be disrupted in a transposon‐induced mutant of Ralstonia eutropha exhibiting the phenotype 4‐hydroxybutyric acid‐leaky. The native gab D gene was cloned by colony hybridization using a homologous gab D‐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 gab D 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 γ‐aminobutyrate are closely related to gab D in R. eutropha . Enzymatic studies indicated the existence of a second NAD + ‐dependent succinate semialdehyde dehydrogenase in R. eutropha .