Functional significance of the Cu,ZnSOD in Escherichia coli.
Diethyl dithiocarbamate (DDC) was used to inhibit the copper- and zinc- containing superoxide dismutase (Cu,ZnSOD) of Escherichia coli in order to expose its physiological function. DDC inhibited the aerobic growth of a sodA sodB mutant much more than it did the growth of a SOD-replete parental strain and this inhibitory effect was oxygen-dependent. The SOD mimic MnTMPyP markedly diminished the growth inhibitory effect of DDC. Transfer of the sodA sodB strain from anaerobic to aerobic conditions induced fumarase C, which is a member of the soxRS regulon. DDC augmented this induction. These results indicate that the Cu,ZnSOD provides a defense against oxidative stress, which is more important to the sodA sodB mutant than to its SOD-replete parental strain.
Benov
L
L
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
Fridovich
I
I
D000332:Aerobiosis; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004050:Ditiocarb / Q000494:pharmacology*; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005649:Fumarate Hydratase / Q000096:biosynthesis; D005798:Genes, Bacterial; D007700:Kinetics; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D004050:Ditiocarb; C095500:SodA protein, Bacteria; C087504:SodB protein, Bacteria; D013482:Superoxide Dismutase; D005649:Fumarate Hydratase