title: 2.8-A-resolution crystal structure of an active-site mutant of aspartate aminotransferase from Escherichia coli.
abstract: The three-dimensional structure of a mutant of the aspartate aminotransferase from Escherichia coli, in which the active-site lysine has been substituted by alanine (K258A), has been determined at 2.8-A resolution by X-ray diffraction. The mutant enzyme contains pyridoxamine phosphate as cofactor. The structure is compared to that of the mitochondrial aspartate aminotransferase. The most striking differences, aside from the absence of the lysine side chain, occur in the positions of the pyridoxamine group and of tryptophan 140.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: D L
authors.initials: DL
authors.lastname: Smith
authors.forename: S C
authors.initials: SC
authors.lastname: Almo
authors.forename: M D
authors.initials: MD
authors.lastname: Toney
authors.forename: D
authors.initials: D
authors.lastname: Ringe
mesh_terms: D001219:Aspartate Aminotransferases / Q000032:analysis / Q000235:genetics*; D001665:Binding Sites; D003460:Crystallization; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D008239:Lysine / Q000032:analysis; D009154:Mutation; D011487:Protein Conformation; D011732:Pyridoxal Phosphate; D012545:Schiff Bases; D014961:X-Ray Diffraction
chemical_list: D012545:Schiff Bases; D011732:Pyridoxal Phosphate; D001219:Aspartate Aminotransferases; D008239:Lysine