title: The multisubunit active site of fumarase C from Escherichia coli.
abstract: The crystal structure of the tetrameric enzyme, fumarase C from Escherichia coli, has been determined to a resolution of 2.0 A. A tungstate derivative used in the X-ray analysis is a competitive inhibitor and places the active site of fumarase in a region which includes atoms from three of the four subunits. The polypeptide conformation is similar to that of delta-crystallin and is comprised of three domains. The central domain, D2, is a unique five-helix bundle. The association of the D2 domains results in a tetramer which has a core of 20 alpha-helices. The other two domains, D1 and D3, cap the helical bundle on opposite ends giving both the single subunit and the tetramer a dumbbell-like appearance. Fumarase C has sequence homology to the eukaryotic fumarases, aspartase, arginosuccinate lyase, adenylosuccinate lyase and delta-crystallin.
authors.affiliation: Department of Biochemistry, University of Minnesota, Minneapolis 55455, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Weaver
authors.forename: D G
authors.initials: DG
authors.lastname: Levitt
authors.forename: M I
authors.initials: MI
authors.lastname: Donnelly
authors.forename: P P
authors.initials: PP
authors.lastname: Stevens
authors.forename: L J
authors.initials: LJ
authors.lastname: Banaszak
mesh_terms: D000264:Adenylosuccinate Lyase / Q000737:chemistry; D000595:Amino Acid Sequence; D001123:Argininosuccinate Lyase / Q000737:chemistry; D001220:Aspartate Ammonia-Lyase / Q000737:chemistry; D001483:Base Sequence; D001665:Binding Sites; D003198:Computer Simulation; D003459:Crystallins / Q000737:chemistry; D018360:Crystallography, X-Ray; D017931:DNA Primers; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005649:Fumarate Hydratase / Q000737:chemistry* / Q000378:metabolism; D005798:Genes, Bacterial; D007700:Kinetics; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D003459:Crystallins; D017931:DNA Primers; D046911:Macromolecular Substances; D011994:Recombinant Proteins; C095842:fumarase C; D005649:Fumarate Hydratase; D001220:Aspartate Ammonia-Lyase; D001123:Argininosuccinate Lyase; D000264:Adenylosuccinate Lyase