title: Succinic semialdehyde reductase Gox1801 from Gluconobacter oxydans in comparison to other succinic semialdehyde-reducing enzymes.
abstract: Gluconobacter oxydans is an industrially important bacterium that possesses many uncharacterized oxidoreductases, which might be exploited for novel biotechnological applications. In this study, gene gox1801 was homologously overexpressed in G. oxydans and it was found that the relative expression of gox1801 was 13-fold higher than that in the control strain. Gox1801 was predicted to belong to the 3-hydroxyisobutyrate dehydrogenase-type proteins. The purified enzyme had a native molecular mass of 134 kDa and forms a homotetramer. Analysis of the enzymatic activity revealed that Gox1801 is a succinic semialdehyde reductase that used NADH and NADPH as electron donors. Lower activities were observed with glyoxal, methylglyoxal, and phenylglyoxal. The enzyme was compared to the succinic semialdehyde reductase GsSSAR from Geobacter sulfurreducens and the γ-hydroxybutyrate dehydrogenase YihU from Escherichia coli K-12. The comparison revealed that Gox1801 is the first enzyme from an aerobic bacterium reducing succinic semialdehyde with high catalytic efficiency. As a novel succinic semialdehyde reductase, Gox1801 has the potential to be used in the biotechnological production of γ-hydroxybutyrate.
authors.affiliation: Institute of Microbiology and Biotechnology, Meckenheimer Allee 168, 53115, Bonn, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Meyer
authors.forename: Paul
authors.initials: P
authors.lastname: Schweiger
authors.forename: Uwe
authors.initials: U
authors.lastname: Deppenmeier
mesh_terms: D003067:Coenzymes / Q000378:metabolism; D015870:Gene Expression; D020600:Gluconobacter oxydans / Q000201:enzymology* / Q000235:genetics; D006884:Hydroxybutyrate Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D055503:Protein Multimerization; D013379:Substrate Specificity; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D003067:Coenzymes; D009243:NAD; D009249:NADP; D005680:gamma-Aminobutyric Acid; D006884:Hydroxybutyrate Dehydrogenase; C019416:4-hydroxybutyrate dehydrogenase; C009338:succinic semialdehyde