Chlorite dismutase from Ideonella dechloratans.
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.
Stenklo
K
K
Department of Chemistry, Karlstad University, Sweden.
Thorell
H D
HD
Bergius
H
H
Aasa
R
R
Nilsson
T
T
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
D006418:Heme; D010088:Oxidoreductases; C402794:chlorite dismutase