title: Citrate synthase and 2-methylcitrate synthase: structural, functional and evolutionary relationships.
abstract: Following the complete sequencing of the Escherichia coli genome, it has been shown that the proposed second citrate synthase of this organism, recently described by the authors, is in fact a 2-methylcitrate synthase that possesses citrate synthase activity as a minor component. Whereas the hexameric citrate synthase is constitutively produced, the 2-methylcitrate synthase is induced during growth on propionate, and the catabolism of propionate to succinate and pyruvate via 2-methylcitrate is proposed. The citrate synthases of the psychrotolerant eubacterium DS2-3R, and of the thermophilic archaea Thermoplasma acidophilum and Pyrococcus furiosus, are approximately 40% identical in sequence to the Escherichia coli 2-methylcitrate synthase and also possess 2-methylcitrate synthase activity. The data are discussed with respect to the structure, function and evolution of citrate synthase and 2-methylcitrate synthase.
authors.affiliation: Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
authors.forename: Ursula
authors.initials: U
authors.lastname: Gerike
authors.affiliation: Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
authors.forename: David W
authors.initials: DW
authors.lastname: Hough
authors.affiliation: Department of Biological Sciences, Wye College, University of London, Wye, Kent TN25 5AH, UK.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Russell
authors.affiliation: Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3052, Australia.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Dyall-Smith
authors.affiliation: Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Danson
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development; D005798:Genes, Bacterial; D007652:Oxo-Acid-Lyases / Q000032:analysis / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002950:Citrate (si)-Synthase; C112399:2-methylcitrate synthase; D007652:Oxo-Acid-Lyases