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The twin arginine transport system appears to be essential for viability in Sinorhizobium meliloti

Brad S Pickering1, Ivan J Oresnik

  • 1Department of Microbiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.

Journal of Bacteriology
|August 3, 2010
PubMed

Insights

The twin arginine transport (Tat) system in Sinorhizobium meliloti is essential for cell viability. Disrupting the tatABC genes leads to cell death, indicating its critical role in bacterial survival.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacterial Physiology

Background:

  • The twin arginine transport (Tat) system facilitates the translocation of prefolded proteins across the inner membrane in bacteria.
  • The Tat pathway is crucial for various cellular processes, including motility, biofilm formation, and pathogenesis.
  • Sinorhizobium meliloti Rm1021 possesses a large number of putative Tat substrates, suggesting a significant role for this system.

Purpose of the Study:

  • To investigate the essentiality of the twin arginine transport (Tat) system in Sinorhizobium meliloti.
  • To characterize the function of the tatABC genes within the S. meliloti Tat pathway.
  • To understand the implications of Tat system disruption on bacterial viability.

Main Methods:

  • Targeted mutagenesis of the tat locus in S. meliloti.
  • Construction of merodiploid strains for tatABC complementation.
  • Plasmid stability assays in tat deletion backgrounds.
  • Fluorescence microscopy and live/dead cell assays to assess viability.

Main Results:

  • Attempts at tat locus mutagenesis were unsuccessful without tatABC complementation.
  • A plasmid carrying tatABC remained stable in a tat deletion strain without antibiotic selection.
  • Loss of tatABC resulted in a high proportion of dead and irregularly shaped cells.

Conclusions:

  • The twin arginine transport (Tat) system, specifically the tatABC genes, appears to be essential for the viability of Sinorhizobium meliloti under tested conditions.
  • Disruption of the Tat system leads to significant cell death, highlighting its critical role in maintaining bacterial integrity.
  • Further characterization of the Tat pathway in S. meliloti is warranted due to its apparent essentiality.

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