Human copper-zinc superoxide dismutase complements superoxide dismutase-deficient Escherichia coli mutants.

Human copper-zinc superoxide dismutase complements superoxide dismutase-deficient Escherichia coli mutants.

An Escherichia coli double mutant, sodAsodB, that is deficient in both bacterial superoxide dismutases (Mn superoxide dismutase and iron superoxide dismutase) is unable to grow on minimal medium in the presence of oxygen and exhibits increased sensitivity to paraquat and hydrogen peroxide. Expression of the evolutionarily unrelated eukaryotic CuZn superoxide dismutase in the sodAsodB E. coli mu...

Escherichia coli expresses a copper- and zinc-containing superoxide dismutase.

A mutant of Escherichia coli, unable to produce manganese- or iron-containing superoxide dismutase (SOD), was found to contain modest levels of an SOD that was judged to be a copper- and zinc-containing SOD on the basis of inhibition by cyanide and inactivation by either H2O2 or diethyldithiocarbamate. Moreover, the diethyldithiocarbamate-inactivated enzyme could be reactivated with Cu(II), and...

Total reconstitution of copper-zinc superoxide dismutase.

The total reconstitution of copper-zinc superoxide dismutase by stoichiometric addition of the metals to completely metal-free apoprotein is described. Reconstitution has been monitored by electron paramagnetic resonance (EPR) and absorption spectroscopy, enzymic activity, and acrylamide gel el%ctrophoresis. Under the same conditions, it has been possible to prepare highly active enzymes with c...

Superoxide dismutase Superoxide dismutase

Control of Escherichia coli Superoxide Dismutase

The ferric uptake regulation (fur) gene product participates in regulating expression of the manganeseand iron-containing superoxide dismutase genes of Escherichia coli. Examination of ,-galactosidase activity coded from a chromosomal d(sodA'-'lacZ) fusion suggests that metallated Fur protein acts as a transcriptional repressor of sodA (manganese superoxide dismutase [MnSOD]). Gel retardation a...