Potassium Pathways in Escherichia coli
Prokaryotes and Escherichia coli in particular do not possess (Na, K) ATPase in their plasma membrane like higher eukaryotes. Nevertheless, K+ is the predominant cytoplasmic cation and it is essential for growth. The reason for the absolute requirement for potassium in prokaryotes as in eukaryotes is not entirely understood. One role of potassium is, however, probably specific to bacteria, namely the necessity to maintain an osmotic pressure in the cytoplasm in excess of the osmotic pressure in the medium, so that a hydrostatic pressure, the turgor pressure, keeps the plasma membrane in close contact with the rigid murein layer.
KeywordsOsmotic Pressure Turgor Pressure Carbon Starvation Potassium Transport Triphenyl Phosphonium
Unable to display preview. Download preview PDF.
- Helmer, G. L., Laimins, L. A., and Epstein, W., 1982, Mechanisms of potassium transport in bacteria, in: Membranes and Transport, Vol. 2 (A. Martonosi, ed.), Plenum Press, New York and London, pp. 123–128.Google Scholar
- Kepes, A., Meury, J., Robin, A., and Jimeno, J., 1977, Some ion transport systems in E. coli (transport of potassium and anionic sugars), in: Biochemistry of Membrane Transport,FEBS Symposium 42 (G. Semenza and E. Carafoli, eds.), Springer-Verlag, Berlin, Heidelberg, pp. 633–647.CrossRefGoogle Scholar
- Meury, J., and Kepes, A., 1982, Glutathione and the gated potassium channels of Escherichia coli, Eur. Mol. Biol. Org. J. 1:339–343.Google Scholar
- Silver, S., 1978, Transport of cations and anions, in: Bacterial Transport (B. Rosen, ed.), Marcel Dekker, New York, pp. 221–324.Google Scholar