Nucleotide parasitism by Simkania negevensis (Chlamydiae).

Author(s)
Silvia Knab, Tanja Mushak, Stephan Schmitz-Esser, Matthias Horn, I Haferkamp
Abstract

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 in Escherichia 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.

Organisation(s)
External organisation(s)
Technische Universität Kaiserslautern
Journal
Journal of Bacteriology
Volume
193
Pages
225-235
No. of pages
11
ISSN
0021-9193
DOI
https://doi.org/10.1128/JB.00919-10
Publication date
2011
Peer reviewed
Yes
Austrian Fields of Science 2012
106008 Botany
Portal url
https://ucrisportal.univie.ac.at/en/publications/08c2c884-8d25-4b00-91cd-dcb8915c5da4