title: Dialkylglycine decarboxylase structure: bifunctional active site and alkali metal sites.
abstract: The structure of the bifunctional, pyridoxal phosphate-dependent enzyme dialkylglycine decarboxylase was determined to 2.1-angstrom resolution. Model building suggests that a single cleavage site catalyzes both decarboxylation and transamination by maximizing stereoelectronic advantages and providing electrostatic and general base catalysis. The enzyme contains two binding sites for alkali metal ions. One is located near the active site and accounts for the dependence of activity on potassium ions. The other is located at the carboxyl terminus of an alpha helix. These sites help show how proteins can specifically bind alkali metals and how these ions can exert functional effects.
authors.affiliation: Department of Structural Biology, University of Basel, Switzerland.
authors.forename: M D
authors.initials: MD
authors.lastname: Toney
authors.forename: E
authors.initials: E
authors.lastname: Hohenester
authors.forename: S W
authors.initials: SW
authors.lastname: Cowan
authors.forename: J N
authors.initials: JN
authors.lastname: Jansonius
mesh_terms: D000586:Amination; D000595:Amino Acid Sequence; D001665:Binding Sites; D002262:Carboxy-Lyases / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D003196:Computer Graphics; D003653:Decarboxylation; D008672:Metals, Alkali / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014961:X-Ray Diffraction
chemical_list: D008672:Metals, Alkali; D002262:Carboxy-Lyases; C063519:2,2-dialkylglycine decarboxylase