Oxidative phosphorylation in Escherichia coli K-12: The genetic and biochemical characterisation of a strain carrying a mutation in the uncB gene
| Autor: | Graeme B. Cox, Frank Gibson, J. D. Butlin |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Genetics
Microbial Vitamin K Ubiquinone ATPase Mutant Biophysics Oxidative phosphorylation medicine.disease_cause Biochemistry Oxidative Phosphorylation Electron Transport Transduction Genetic Flavins Escherichia coli medicine NADH NADPH Oxidoreductases Anaerobiosis Gene Adenosine Triphosphatases Mutation biology Cell Membrane Structural gene Chromosome Mapping Cell Biology Molecular biology Aerobiosis Glucose Genes Models Chemical Lactates biology.protein Cytochromes Energy source |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Bioenergetics. 292:366-375 |
| ISSN: | 0005-2728 |
| DOI: | 10.1016/0005-2728(73)90043-1 |
| Popis: | 1. A mutant strain of Escherichia coli unable to grow with succinate as sole carbon source was isolated. This mutant was found to carry a mutation in a gene (designated uncB) mapping at about minute 73.5 on the E. coli chromosome and close to the uncA gene which is probably the structural gene for (Mg2+,Ca2+)-stimulated ATPase. 2. The uncB401 allele was transduced into two other strains of E. coli and the transductants compared with the parent strains. 3. Strains carrying the uncB401 allele have low aerobic growth yields when grown on limiting concentrations of glucose, but unlike mutations in the uncA gene, mutations in the uncB gene do not impair anaerobic growth on a glucose-mineral salts medium. 4. Oxidase activities in membranes from the normal strains and strains carrying the uncB401 allele were similar. 5. Measurement of P/O ratios indicated that a mutation in the uncB gene causes uncoupling of phosphorylation associated with electron transport with d-lactate as substrate. 6. (Mg2+,Ca2+)-stimulated ATPase activities in the normal strains and in strains carrying the uncB401 allele are similar. 7. Estimation of the energy-linked and non-energy-linked transhydrogenase activities in membrane preparations from both the normal and mutant strains indicated that the protein affected by a mutation in the uncB gene is essential for the functioning of the ATP-dependent energy-linked transhydrogenase. 8. It is concluded that two proteins, specified by the uncA and uncB genes, are essential for phosphorylation coupled to d-lactate oxidation and also for the energy-linked transhydrogenase activity using ATP as the energy source. |
| Databáze: | OpenAIRE |
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