Isolation of superoxide dismutase mutants in Escherichia coli: is superoxide dismutase necessary for aerobic life?

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...

Superoxide dismutase protects against aerobic heat shock in Escherichia coli.

Exposure of a superoxide dismutase-null (sodA sodB) strain of Escherichia coli to aerobic heat stress (45 to 48 degrees C) caused a profound loss of viability, whereas the same heat stress applied anaerobically had a negligible effect. A superoxide dismutase-competent parental strain was resistant to the lethal effect of the aerobic heating. It follows that aerobic heating imposes an oxidative ...

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...

Regulation of Superoxide Dismutase Synthesis in Escherichia coli: Glucose Effect

Growth of Escherichia coli based upon the fermentation of glucose, is associated with a low intracellular level of superoxide dismutase. Exhaustion of glucose, or depression of the pH due to accumulation of organic acids, causes these organisms to then obtain energy from the oxidative degradation of other substances present in a rich medium. This shift in metabolism is associated with a marked ...