Specific cesium transport via the Escherichia coli Kup (TrkD) K+ uptake system

J Bacteriol. 1989 Apr;171(4):2219-21. doi: 10.1128/jb.171.4.2219-2221.1989.


Escherichia coli cells which contain a functional Kup (formerly TrkD) system took up Cs+ with a moderate rate and affinity. Kup is a separate K+ uptake system with relatively little discrimination in the transport of the cations K+, Rb+, and Cs+. Regardless of the presence or absence of Kup, K+-replete cells took up Cs+ primarily by a very low affinity mode, proportional to the ratio of the Cs+ and K+ concentrations in the medium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding, Competitive
  • Biological Transport
  • Cesium / metabolism*
  • DNA Mutational Analysis
  • Escherichia coli / metabolism*
  • Genes, Bacterial
  • Kinetics
  • Potassium / metabolism*
  • Recombinant Proteins / metabolism
  • Substrate Specificity


  • Recombinant Proteins
  • Cesium
  • Potassium