title: Structure of the catalytic domain of glucoamylase from Aspergillus niger.
abstract: Glucoamylase from Aspergillus niger is an industrially important biocatalyst that is utilized in the mass production of glucose from raw starch or soluble oligosaccharides. The G1 isoform consists of a catalytic domain and a starch-binding domain connected by a heavily glycosylated linker region. The amino-terminal catalytic domain of the G1 isoform generated by subtilisin cleavage has been crystallized at pH 8.5, which is a significantly higher pH condition than used for previously characterized glucoamylase crystals. The refined structure at 1.9 Å resolution reveals the active site of the enzyme in complex with both Tris and glycerol molecules. The ligands display both unique and analogous interactions with the substrate-binding site when compared with previous structures of homologous enzymes bound to inhibitors.
authors.affiliation: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Jaeyong
authors.initials: J
authors.lastname: Lee
authors.forename: Mark
authors.initials: M
authors.lastname: Paetzel
mesh_terms: D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000201:enzymology* / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D017124:Conserved Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000737:chemistry; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D021382:Protein Sorting Signals; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012995:Solubility; D013213:Starch / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D014867:Water / Q000737:chemistry
chemical_list: D004220:Disulfides; D007527:Isoenzymes; D008024:Ligands; D010455:Peptides; D021382:Protein Sorting Signals; D014867:Water; D013213:Starch; D005087:Glucan 1,4-alpha-Glucosidase