The <i>tol</i> gene products and the import of macronmolecules into <i>Escherichia coli</i>

Webster, Reginald P.

doi:10.1111/j.1365-2958.1991.tb01873.x

Cited by 251 publications

(258 citation statements)

References 54 publications

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“…␤3a and ␤3b curve around the ␤-barrel at almost 90 o to each other. ␤3b is connected to another long strand, ␤4 (53)(54)(55)(56)(57)(58)(59)(60)(61)(62), by a type I hairpin turn. The ␤3␤4 hairpin extends away from the top of the ␤-barrel.…”

Section: Resultsmentioning

confidence: 99%

Crystal Structures of a CTXφ pIII Domain Unbound and in Complex with a Vibrio cholerae TolA Domain Reveal Novel Interaction Interfaces

Ford

Kolappan

Phan

et al. 2012

Journal of Biological Chemistry

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Background: CTX infection of Vibrio cholerae confers toxigenicity. Results: We report crystal structures of CTX-pIII domain N1 alone and bound to V. cholerae TolA domain C. Conclusion: CTX and coliphage pIII use distinct mechanisms to bind to TolA. Significance: These structures contribute to our understanding of a critical step in the evolution of pandemic V. cholerae with implications for emerging V. cholerae pathogens.

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Section: Resultsmentioning

confidence: 99%

Crystal Structures of a CTXφ pIII Domain Unbound and in Complex with a Vibrio cholerae TolA Domain Reveal Novel Interaction Interfaces

Ford

Kolappan

Phan

et al. 2012

Journal of Biological Chemistry

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“…Alanine scanning mutagenesis of the putative TolA boxes of colicin K and colicin N would be very informative. Progress in our understanding of the translocation of colicins will require knowledge of the three-dimensional structures of the translocation domain of Tol-dependent colicins, as has recently been obtained for the TonB-dependent colicin Ia (Wiener et al, 1997), together with the development of an in uitro or in uiuo assay of translocation. The alanine mutants described in this work will be of value in dissecting the role of any interaction with proteins of the translocation machinery in the biological activity of colicin E9.…”

Section: Discussionmentioning

confidence: 99%

Identification of residues in the putative TolA box which are essential for the toxicity of the endonuclease toxin colicin E9

et al. 1997

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E colicins are plasmid-coded, protein antibiotics which bind to the BtuB outer membrane receptor of Escheriehia coli cells and are then translocated either to the outer surface of the cytoplasmic membrane in the case of the pore-forming colicin El, or to the cytoplasm in the case of the enzymic colicins E2-E9. Translocation has been proposed to be dependent on a putative TolA box; a pentapeptide (DGSGW) located in the N-terminal39 residues of several Toldependent colicins. In this study, site-directed mutagenesis was used to change each of the residues of the putative TolA box of coljcin E9 to alanines.In the case of the two glycine residues, the resulting mutant proteins were indistinguishable from the native colicin E9 protein in a biological assay; whereas the other three residues when mutated to alanines resulted in a complete loss of biological activity. Mutagenesis of two serine residues flanking the putative TolA box, Ser34 and Sera, to alanines did not abolish the biological activity of the mutant colicin E9, although the zones of growth inhibition were hazy and slow to form. The size of the zone of inhibition was significantly smaller than the control in the case of the Ser40Ala mutant. The ColE9/lm9 complex was isolated from the three biologically inactive TolA box alanine mutants. In competition assays all three mutant protein complexes were capable of protecting sensitive E. coli cells against killing by the native ColE9/lm9 complex. On removal of the lm9 protein from the three mutant ColE9/lm9 complexes, all three mutant colicins exhibited DNase activity. These results confirm the importance of the putative TolA box in the biological activity of colicin E9, and suggest that the TolA box has a role in the translocation of colicin E9.

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“…By contrast, there have been few studies aimed at understanding how the cytotoxic domains of enzymatic colicins cross the cytoplasmic membrane of bacteria. It is not clear, for example, whether accessory proteins, such as the Tol proteins that are known from E. coli mutants to be needed for translocation 7 , are involved directly in this process or whether the toxin can translocate across the cytoplasmic membrane unaided. In order to begin addressing these questions we investigated the interactions of the endonuclease toxin colicin E9 with membranes in planar lipid bilayer experiments.…”

Section: Colicin E9 Forms Channels In Membranesmentioning

confidence: 99%

The cytotoxic domain of colicin E9 is a channel-forming endonuclease

et al. 2002

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Article:Mosbahi, Khédidja, Lemaître, Christelle, Mobasheri, Hamid et al. (6 more authors) (2002) The cytotoxic domain of colicin E9 is a channel-forming endonuclease. Nature Structural Biology. pp. 476-484. ISSN 1545-9985 https://doi.org/10.1038/nsb797 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. White Rose Consortium ePrints Repositoryhttp://eprints.whiterose.ac.uk/ This is an author produced version of a paper published in Nature Structural Biology. This paper has been peer-reviewed but does not include final publisher proof-corrections or journal pagination.White Rose Repository URL for this paper: http://eprints.whiterose.ac.uk/archive/00001066/ Citation for the published paper Mosbahi, Khédidja and Lemaître, Christelle and Keeble, Anthony H. and Mobasheri, Hamid and Morel, Bertrand and James, Richard and Moore, Geoffrey R. and Lea, Edward J. A. and Kleanthous, Colin (2002) The cytotoxic domain of colicin E9 is a channel-forming endonuclease. Nature Structural Biology, 9 (6). pp. 476-484. Citation for this paperTo refer to the repository paper, the following format may be used: Mosbahi, Khédidja and Lemaître, Christelle and Keeble, Anthony H. and Mobasheri, Hamid and Morel, Bertrand and James, Richard and Moore, Geoffrey R. and Lea, Edward J. A. and Kleanthous, Colin (2002) Colicin E9 is a 60 kDa toxin that is normally released from colicinogenic bacteria in the form of a heterodimeric complex with its 9.5 kDa immunity protein, Im9 (ref. 14). The immunity protein protects the colicin-producing bacterium from the activity of its own toxin but is jettisoned on entry of the colicin into a susceptible cell 15 . Hence, the form of the toxin tested in the bilayer experiments had the immunity protein removed (see Materials andMethods section). Previous work from our laboratory has shown that this form of the toxin retains complete biological activity 14 . Immunity-free colicin E9 (2 nM) was added to the cis chamber of a bilayer apparatus in 10 mM Tris/HCl buffer at pH 7.5, containing 0.1 M NaCl and 10 mM CaCl 2 , and a potential difference (p.d.) applied across the membrane. Random, fluctuating current was observed that showed evidence of opening and closing events with conductance of the order of ~100 pS, although larger conductance states were also seen ( Fig. 1a). In order to identify the region(s) of the protein responsible for this a...

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The tol gene products and the import of macronmolecules into Escherichia coli

Cited by 251 publications

References 54 publications

Crystal Structures of a CTXφ pIII Domain Unbound and in Complex with a Vibrio cholerae TolA Domain Reveal Novel Interaction Interfaces

Crystal Structures of a CTXφ pIII Domain Unbound and in Complex with a Vibrio cholerae TolA Domain Reveal Novel Interaction Interfaces

Identification of residues in the putative TolA box which are essential for the toxicity of the endonuclease toxin colicin E9

The cytotoxic domain of colicin E9 is a channel-forming endonuclease

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