Abstract
To study how changes in the (ATP)/(ADP) ratio affect the level of DNA supercoiling in Escherichia coli, the cellular content of H+-ATPase was modulated around the wild-type level. A relatively large drop in the (ATP)/(ADP) ratio from the normal ratio resulted in a small increase in the linking number of our reporter plasmid (corresponding to a small decrease in negative supercoiling). However, when cells depleted their carbon and energy source, the ensuing drop in energy state was accompanied by a strong increase in linking number. This increase was not due to reduced transcription of the DNA in the absence of growth substrate, since rifampin had virtually no effect on the plasmid linking number. To examine whether DNA supercoiling depends more strongly on the cellular energy state at low (ATP)/(ADP) ratios than at high ratios, we used cells that were already at a low energy state after substrate depletion; after the addition of an uncoupler to these cells, the (ATP)/(ADP) ratio decreased further, which resulted in a strong increase in plasmid linking number. Our results suggest that the strong thermodynamic control of DNA supercoiling takes over at low (ATP)/(ADP) ratios, whereas at high ratios homeostatic control mechanisms attenuate thermodynamic control.
Original language | English |
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Journal | Journal of Bacteriology |
Volume | 177 |
Issue number | 12 |
Pages (from-to) | 3420-3426 |
Number of pages | 7 |
ISSN | 0021-9193 |
DOIs | |
Publication status | Published - 1995 |
Keywords
- Adenosine Diphosphate
- Adenosine Triphosphate
- Cell Division
- DNA, Bacterial
- DNA, Superhelical
- Energy Metabolism
- Escherichia coli
- Glucose
- Proton-Translocating ATPases
- Succinates
- Succinic Acid
- Transcription, Genetic
- 61D2G4IYVH Adenosine Diphosphate
- 8L70Q75FXE Adenosine Triphosphate
- AB6MNQ6J6L Succinic Acid
- EC 3.6.3.14 Proton-Translocating ATPases
- IY9XDZ35W2 Glucose
- ADP
- ATP
- ATPASE
- CARBON SOURCE
- CHROMOSOME
- ENERGY SOURCE
- ENERGY STATE
- GROWTH SUBSTRATES
- HOMEOSTATIC CONTROL MECHANISMS
- NEGATIVE SUPERCOILING
- PLASMID LINKING NUMBER
- THERMODYNAMICS
- TRANSCRIPTION
- Facultatively Anaerobic Gram-Negative Rods Eubacteria Bacteria Microorganisms (Bacteria, Eubacteria, Microorganisms) - Enterobacteriaceae [06702] Escherichia coli
- ADP 58-64-0Q, 4792-83-0Q, 7722-76-1Q, 19429-39-1Q, 175832-20-9Q
- ATP 56-65-5Q, 42530-29-0Q, 94587-45-8Q, 111839-44-2Q
- ATPASE 9000-83-3
- CARBON 7440-44-0
- 10010, Comparative biochemistry
- 10050, Biochemistry methods - General
- 10052, Biochemistry methods - Nucleic acids, purines and pyrimidines
- 10060, Biochemistry studies - General
- 10062, Biochemistry studies - Nucleic acids, purines and pyrimidines
- 10064, Biochemistry studies - Proteins, peptides and amino acids
- 10300, Replication, transcription, translation
- 10506, Biophysics - Molecular properties and macromolecules
- 10614, External effects - Temperature as a primary variable
- 10808, Enzymes - Physiological studies
- 13002, Metabolism - General metabolism and metabolic pathways
- 13003, Metabolism - Energy and respiratory metabolism
- 13014, Metabolism - Nucleic acids, purines and pyrimidines
- 13202, Nutrition - General studies, nutritional status and methods
- 30500, Morphology and cytology of bacteria
- 31000, Physiology and biochemistry of bacteria
- 31500, Genetics of bacteria and viruses
- 32000, Microbiological apparatus, methods and media
- Biochemistry and Molecular Biophysics
- Cell Biology
- Enzymology
- Genetics
- Metabolism
- Methods and Techniques
- Molecular Genetics
- Nutrition
- Physiology
- ESCHERICHIA coli