Escherichia coli strains blocked in Tat-dependent protein export exhibit pleiotropic defects in the cell envelope.
The Tat system is a recently discovered protein export pathway that serves to translocate folded proteins, often containing redox cofactors, across the bacterial cytoplasmic membrane. Here we report that tat strains are associated with a mutant cell septation phenotype, where chains of up to 10 cells are evident. Mutant strains are also hypersensitive to hydrophobic drugs and to lysis by lysozyme in the absence of EDTA, and they leak periplasmic enzymes, characteristics that are consistent with an outer membrane defect. Both phenotypes are similar to those displayed by strains carrying point mutations in the lpxC (envA) gene. The phenotype was not replicated by mutations affecting synthesis and/or activity of all known or predicted Tat substrates.
Stanley
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NR
Centre for Metalloprotein Spectroscopy and Biology, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
Findlay
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K
Berks
B C
BC
Palmer
T
T
D000581:Amidohydrolases / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017101:Bacteriophage P1 / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics* / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D003902:Detergents / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D008854:Microscopy, Electron; D009113:Muramidase / Q000494:pharmacology; D009154:Mutation; D019897:Periplasm / Q000502:physiology; D021381:Protein Transport; D012260:Ribonucleases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D003902:Detergents; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C408585:twin-arginine translocase complex, E coli; D012260:Ribonucleases; D009113:Muramidase; D000581:Amidohydrolases; C097307:UDP-3-O-acyl-N-acetylglucosamine deacetylase