Electron transport reactions in a cytochrome c-deficient mutant of Paracoccus denitrificans.
A mutant of Paracoccus denitrificans which is deficient in c-type cytochromes grows aerobically with generation times similar to those obtained with a wild-type strain. The aa3-type oxidase is functional in the mutant as judged by spectrophotometric assays of cytochrome c oxidation using the membrane particles and cytochrome aa3 reduction in whole cells. The cytochrome c oxidase (aa3-type) of the c-less mutant oxidizes soluble cytochrome c at rates equivalent to those obtained with the wild-type. NADH and succinate oxidase activities of the membrane preparations of the mutant and wild-type are also comparable in the absence of detergent treatment. Exogenous soluble cytochrome c can be both reduced by NADH- and succinate-linked systems and oxidized by cytochrome aa3 present in membranes of the mutant strain. Rapid overall electron transport can occur in the c-less mutant, suggesting that reactions result from collision of diffusing complexes.
Bolgiano
B
B
Department of Microbiology, University of Pennsylvania, School of Medicine, Philadelphia 19104-6076.
Smith
L
L
Davies
H C
HC
D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003574:Cytochrome c Group / Q000235:genetics / Q000502:physiology*; D003902:Detergents / Q000494:pharmacology; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism; D009154:Mutation; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D010101:Oxygen Consumption; D010231:Paracoccus denitrificans / Q000235:genetics / Q000378:metabolism*; D013053:Spectrophotometry; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid
D003574:Cytochrome c Group; D003902:Detergents; D013386:Succinates; D009243:NAD; D019802:Succinic Acid; D010088:Oxidoreductases; C022691:succinate oxidase; D003576:Electron Transport Complex IV