title: The structure of glyceraldehyde 3-phosphate dehydrogenase from Alcaligenes xylosoxidans at 1.7 A resolution.
abstract: The enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the Gram-negative denitrifying bacterial species Alcaligenes xylosoxidans was purified and crystallized as a contaminant protein during purification of nitrous oxide reductase. This is the first structure of a GAPDH from a denitrifying species. The crystal structure was solved at 1.7 A resolution by molecular replacement using the structure of GAPDH from Bacillus stearothermophilus as a starting model. The quality of the structure enabled the amino-acid sequence of the A. xylosoxidans GAPDH to be assigned. The structure is that of the apo-enzyme, lacking the NAD+ cofactor and with the active-site residue Cys154 oxidized. The global structure of the enzyme has a homotetrameric quaternary structure similar to that observed for its bacterial and eukaryotic counterparts. The essential role of Cys154 in the enzyme activity has been confirmed. In monomer O two half-occupancy sulfate ions were found at the active site, which are analogous to the substrate and the "attacking" phosphate seen in B. stearothermophilus. One half-occupancy sulfate ion is also located in the substrate-binding site of monomer P.
authors.affiliation: Molecular Biophysics Group, CCLRC Daresbury Laboratory, Warrington, Cheshire WA4 4AD, England.
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Antonyuk
authors.forename: Robert R
authors.initials: RR
authors.lastname: Eady
authors.forename: Richard W
authors.initials: RW
authors.lastname: Strange
authors.forename: S Samar
authors.initials: SS
authors.lastname: Hasnain
mesh_terms: D042441:Achromobacter denitrificans / Q000201:enzymology*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D001411:Geobacillus stearothermophilus / Q000201:enzymology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011092:Polyethylene Glycols / Q000378:metabolism; D020836:Protein Structure, Quaternary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D011092:Polyethylene Glycols; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases