title: Plausible phosphoenolpyruvate binding site revealed by 2.6 A structure of Mn2+-bound phosphoenolpyruvate carboxylase from Escherichia coli.
abstract: We have determined the crystal structure of Mn2+-bound Escherichia coli phosphoenolpyruvate carboxylase (PEPC) using X-ray diffraction at 2.6 A resolution, and specified the location of enzyme-bound Mn2+, which is essential for catalytic activity. The electron density map reveals that Mn2+ is bound to the side chain oxygens of Glu-506 and Asp-543, and located at the top of the alpha/beta barrel in PEPC. The coordination sphere of Mn2+ observed in E. coli PEPC is similar to that of Mn2+ found in the pyruvate kinase structure. The model study of Mn2+-bound PEPC complexed with phosphoenolpyruvate (PEP) reveals that the side chains of Arg-396, Arg-581 and Arg-713 could interact with PEP.
authors.affiliation: Department of Materials Chemistry, Graduate School of Engineering, Osaka University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Matsumura
authors.forename: M
authors.initials: M
authors.lastname: Terada
authors.forename: S
authors.initials: S
authors.lastname: Shirakata
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Yoshinaga
authors.forename: K
authors.initials: K
authors.lastname: Izui
authors.forename: Y
authors.initials: Y
authors.lastname: Kai
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000737:chemistry; D001665:Binding Sites; D002384:Catalysis; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D008345:Manganese / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry; D010728:Phosphoenolpyruvate / Q000737:chemistry / Q000378:metabolism*; D010730:Phosphoenolpyruvate Carboxylase / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D011770:Pyruvate Kinase / Q000737:chemistry; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
chemical_list: D010446:Peptide Fragments; D001224:Aspartic Acid; D008345:Manganese; D010728:Phosphoenolpyruvate; D011770:Pyruvate Kinase; D010730:Phosphoenolpyruvate Carboxylase