The biology of E colicins: paradigms and paradoxes

James, Richard; Kleanthous, Colin; Moore, Geoffrey R.

doi:10.1099/13500872-142-7-1569

Cited by 226 publications

(166 citation statements)

References 70 publications

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“…In order to begin addressing these questions we investigated the interactions of the endonuclease toxin colicin E9 with membranes in planar lipid bilayer experiments. E9 (and its homologues E2, E7 and E8) is a group A colicin that kills bacteria through non-specific degradation of chromosomal DNA 11,12 . The hypothesis we intended to test was whether DNase colicins have channel forming domains that might be required for translocation of the DNase into the cytoplasm, by analogy with diphtheria toxin which has a channel-forming domain responsible for translocating its ADP-ribosyl transferase into the cytosol of eukaryotic cells 13 .…”

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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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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“…In bacteria, the colicins E3 and E6 are targeted RNases that cleave the small rRNA and kill susceptible bacteria. 2,30 In this regard, they are structurally and functionally reminiscent of RNase fusion proteins genetically engineered to target and kill diseased cells and tissues. 31 Since (À4)EDN is present in humans and inhibits oocyte maturation, a function not shared by the native enzyme, 5,6 it is the ®rst example of a natural human targeted cytotoxic RNase.…”

Section: Structure and Activity Of (à4)ednmentioning

confidence: 99%

Crystallographic and functional studies of a modified form of eosinophil-derived neurotoxin (EDN) with novel biological activities

Chang

Newton

Rybak

et al. 2002

Journal of Molecular Biology

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The crystal structure of a post-translationally modi®ed form of eosinophil-derived neurotoxin (EDN) with four extra residues on its N terminus ((À4)EDN) has been solved and re®ned at atomic resolution (1 A Ê ). Two of the extra residues can be placed unambiguously, while the density corresponding to two others is poor. The modi®ed N terminus appears to in¯uence the position of the catalytically important His129, possibly explaining the diminished catalytic activity of this variant. However, (À4)EDN has been shown to be cytotoxic to a Kaposi's sarcoma tumor cell line and other endothelial cell lines. Analysis of the structure and function suggests that the reason for cytotoxicity is most likely due to cellular recognition by the N-terminal extension, since the intrinsic activity of the enzyme is not suf®cient for cytotoxicity and the N-terminal extension does not affect the conformation of EDN.

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“…The term bacteriocin encompasses an array of structurally different molecules produced by a number of phylogenetically distinct Gram-positive and Gram-negative bacterial groups (Reeves 1972 ;De Vuyst & Vandamme 1994 ;Jack et al 1995). Bacteriocins may act on cells in a variety of different ways (Reeves 1972 ;Jack et al 1995 ;James et al 1996). For example, many bacteriocins, such as mesentericin Y105$( and the B-colicins are membraneactive peptides which act to form pores in the cell membrane of antagonized cells (Fleury et al 1996 ;James et al 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Bacteriocins may act on cells in a variety of different ways (Reeves 1972 ;Jack et al 1995 ;James et al 1996). For example, many bacteriocins, such as mesentericin Y105$( and the B-colicins are membraneactive peptides which act to form pores in the cell membrane of antagonized cells (Fleury et al 1996 ;James et al 1996). These compounds cause leakage of ions and other cellular components, and in so doing disrupt the proton motive force, ultimately resulting in cell death (Abee et al 1994 ;Jack et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Selection and fitness in bacteriocin–producing bacteria

Dykes

Hastings

1997

Proc. R. Soc. Lond. B

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SUMMARYBacteriocins are proteinaceous anticompetitor molecules produced by bacteria against closely related species. A number of theoretical models have been used to explain experimental data that indicate high polymorphisms among bacteriocins and a frequency-dependent nature of selection for bacteriocinproducing strains. The majority of these experimental data were, however, obtained from investigations into the colicin group of bacteriocins produced by Gram-negative bacteria. The conclusions drawn from these models have been extrapolated to other bacteriocins and allelopathic compounds in general. Examination of more recent experimental investigations into the bacteriocins of Gram-positive bacteria indicate a lower degree of polymorphism and a less frequency-dependent mode of selection among these strains than among the colicin-producing strains. Here we examine these contradictions in the light of the assumptions and conclusions of the theoretical models and reported data. We show that fitness costs (as indicated by decreased relative maximum growth rate) associated with bacteriocin production may be much lower in many cases than is assumed in the present models. A lower fitness cost associated with bacteriocin production adequately explains the newer data from Gram-positive bacteria cited here, and indicates that extrapolation of existing models to all bacteriocins and other allelopathic compounds is not appropriate.

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The biology of E colicins: paradigms and paradoxes

Cited by 226 publications

References 70 publications

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

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

Crystallographic and functional studies of a modified form of eosinophil-derived neurotoxin (EDN) with novel biological activities

Selection and fitness in bacteriocin–producing bacteria

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