PMID:19880597
| Citation |
Sikdar, R and Doerrler, WT (2010) Inefficient Tat-dependent export of periplasmic amidases in an Escherichia coli strain with mutations in two DedA family genes. J. Bacteriol. 192:807-18 |
|---|---|
| Abstract |
The DedA family genes are found in most bacterial genomes. Two of these proteins are Escherichia coli YqjA and YghB, predicted inner membrane proteins of unknown function sharing 61% amino acid identity. The E. coli single deletion mutants are largely without phenotype, but the double mutant (BC202; Delta yqjA::Tet(r) Delta yghB::Kan(r)) is characterized by incomplete cell division, temperature sensitivity, and altered phospholipid levels (K. Thompkins et al., J. Bacteriol. 190:4489-4500, 2008). In this report, we have better characterized the cell division chaining defect of BC202. Fluorescence recovery after photobleaching indicates that 58% of the cells in chains are compartmentalized by at least a cytoplasmic membrane. Green fluorescent protein fusions to the cell division proteins FtsZ, ZipA, FtsI, FtsL, and FtsQ are correctly localized to new septation sites in BC202. Periplasmic amidases AmiC and AmiA, secreted by the twin arginine transport (Tat) pathway, are localized to the cytoplasm in BC202. Overexpression of AmiA, AmiC, or AmiB, a periplasmic amidase secreted via the general secretory pathway, restores normal cell division but does not suppress the temperature sensitivity of BC202, indicating that YghB and YqjA may play additional roles in cellular physiology. Strikingly, overexpression of the Tat export machinery (TatABC) results in normal cell division and growth at elevated temperatures. These data collectively suggest that the twin arginine pathway functions inefficiently in BC202, likely due to the altered levels of membrane phospholipids in this mutant. These results underscore the importance of membrane composition in the proper function of the Tat protein export pathway. |
| Links |
PubMed PMC2812453 Online version:10.1128/JB.00716-09 |
| Keywords |
Amidohydrolases/genetics; Amidohydrolases/metabolism; Blotting, Western; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Fluorescence Recovery After Photobleaching; Green Fluorescent Proteins/genetics; Green Fluorescent Proteins/metabolism; Membrane Proteins/genetics; Membrane Proteins/metabolism; Microscopy, Confocal; Mutation; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
See also
References
See Help:References for how to manage references in EcoliWiki.