title: Chlorite dismutase from Ideonella dechloratans.
abstract: Chlorite dismutase has been purified from the chlorate-metabolizing bacterium Ideonella dechloratans. The purified enzyme is tetrameric, with a relative molecular mass of 25,000 for the subunit, and contains about 0.6 heme/subunit as isolated. Its catalytic properties are similar, but not identical, to those found for a similar enzyme purified earlier from the bacterium GR-1. The heme group in Ideonella chlorite dismutase is readily reduced by dithionite, in contrast to the GR-1 enzyme, and redox titration gave a value of -21 mV for the midpoint potential at pH 7. The heme group has been characterized by optical and EPR spectroscopy. It is high-spin ferric at neutral pH, with spectroscopic properties similar to those found for cytochrome c peroxidase. In the alkaline pH range, a low-spin compound is formed. A 22-residue N-terminal amino acid sequence has been determined and no homologue has been found in the protein sequence databases.
authors.affiliation: Department of Chemistry, Karlstad University, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Stenklo
authors.forename: H D
authors.initials: HD
authors.lastname: Thorell
authors.forename: H
authors.initials: H
authors.lastname: Bergius
authors.forename: R
authors.initials: R
authors.lastname: Aasa
authors.forename: T
authors.initials: T
authors.lastname: Nilsson
mesh_terms: D000595:Amino Acid Sequence; D020562:Betaproteobacteria / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D006418:Heme; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D006418:Heme; D010088:Oxidoreductases; C402794:chlorite dismutase