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Nucleotide Parasitism by Simkania negevensis (Chlamydiae)
Journal of Bacteriology (2011)
  • Silvia Knab, University of Vienna
  • Tanja M. Mushak, Technische Universitat Kaiserslautern
  • Stephan Schmitz-Esser, University of Vienna
  • Matthias Horn, University of Vienna
  • Ilka Haferkamp, Technische Universität Kaiserslautern
Intracellular bacteria live in an environment rich in most essential metabolites but need special mechanisms to access these substrates. Nucleotide transport proteins (NTTs) catalyze the import of ATP and other nucleotides from the eukaryotic host into the bacterial cell and render de novo synthesis of these compounds dispensable. The draft genome sequence of Simkania negevensis strain Z, a chlamydial organism considered a newly emerging pathogen, revealed four genes encoding putative nucleotide transport proteins (SnNTT1 to SnNTT4), all of which are transcribed during growth of S. negevensis in Acanthamoeba host cells, as confirmed by reverse transcription-PCR. Using heterologous expression inEscherichia coli, we could show that SnNTT1 functions as an ATP/ADP antiporter,SnNTT2 as a guanine nucleotide/ATP/H+ symporter driven by the membrane potential, and SnNTT3 as a nucleotide triphosphate antiporter. In addition, SnNTT3 is able to transport dCTP, which has not been shown for a prokaryotic transport protein before. No substrate could be identified for SnNTT4. Taking these data together, S. negevensis employs a set of nucleotide transport proteins to efficiently tap its host's energy and nucleotide pools. Although similar to other chlamydiae, these transporters show distinct and unique adaptations with respect to substrate specificities and mode of transport.
Publication Date
January, 2011
Publisher Statement
© 2011, American Society for Microbiology
Citation Information
Silvia Knab, Tanja M. Mushak, Stephan Schmitz-Esser, Matthias Horn, et al.. "Nucleotide Parasitism by Simkania negevensis (Chlamydiae)" Journal of Bacteriology Vol. 193 Iss. 1 (2011) p. 225 - 235
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