title: Kinetic characterization and molecular modeling of NAD(P)(+)-dependent succinic semialdehyde dehydrogenase from Bacillus subtilis as an ortholog YneI.
abstract: Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde (SSA) into succinic acid in the final step of γ-aminobutyric acid degradation. Here, we characterized Bacillus subtilis SSADH (BsSSADH) regarding its cofactor discrimination and substrate inhibition. BsSSADH showed similar values of the catalytic efficiency (kcat/Km) in both NAD(+) and NADP(+) as cofactors, and exhibited complete uncompetitive substrate inhibition at higher SSA concentrations. Further analyses of the sequence alignment and homology modeling indicated that the residues of catalytic and cofactor-binding sites in other SSADHs were highly conserved in BsSSADH.
authors.affiliation: Department of Clinical Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan 609-757, Republic of Korea.
authors.forename: Seong Ah
authors.initials: SA
authors.lastname: Park
authors.forename: Ye Song
authors.initials: YS
authors.lastname: Park
authors.forename: Ki Seog
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D050644:Succinate-Semialdehyde Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D009243:NAD; D009249:NADP; D005680:gamma-Aminobutyric Acid; D050644:Succinate-Semialdehyde Dehydrogenase; C009338:succinic semialdehyde