title: X-ray crystallographic and kinetic correlation of a clinically observed human fumarase mutation.
abstract: Fumarase catalyzes the reversible conversion of fumarate to S- malate during the operation of the ubiquitous Kreb's cycle. Previous studies have shown that the active site includes side chains from three of the four subunits within the tetrameric enzyme. We used a clinically observed human mutation to narrow our search for potential catalytic groups within the fumarase active site. Offspring homozygous for the missense mutation, a G-955-C transversion in the fumarase gene, results in the substitution of a glutamine at amino acid 319 for the normal glutamic acid. To more fully understand the implications of this mutation, a single-step site-directed mutagenesis method was used to generate the homologous substitution at position 315 within fumarase C from Escherichia coli. Subsequent kinetic and X-ray crystal structure analyses show changes in the turnover number and the cocrystal structure with bound citrate.
authors.affiliation: Johns Hopkins University, School of Medicine, Department of Neuroscience, Baltimore, Maryland 21205, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Estévez
authors.forename: Jeremy
authors.initials: J
authors.lastname: Skarda
authors.forename: Josh
authors.initials: J
authors.lastname: Spencer
authors.forename: Leonard
authors.initials: L
authors.lastname: Banaszak
authors.forename: Todd M
authors.initials: TM
authors.lastname: Weaver
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain / Q000235:genetics; D019343:Citric Acid; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D005260:Female; D005649:Fumarate Hydratase / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense
chemical_list: D019343:Citric Acid; D005649:Fumarate Hydratase