Colicin N
From Proteopedia
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==Synthesis and release== | ==Synthesis and release== | ||
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| + | The plasmid encoding the c. 42kDa<ref> PMID: 6327609 </ref> ColN also encodes its corresponding [[Colicin Immunity Protein]], [[Cni]], in order to protect the colicinergic cell from the cytotoxic activity of the colicin. | ||
==Mechanism of uptake== | ==Mechanism of uptake== | ||
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| + | Colicin N parasitizes the outer membrane protein F (OmpF) as both its receptor and its translocator, alongside the [[Tol]] proteins TolQRA. There is evidence to show that the translocation may occur at the protein-lipid interface. ColN binding displaces OmpF-bound lipopolysaccharide, the major lipid in the outer leaflet of the outer membrane. The N terminal region of ColN then rearranges and binds to OmpF<ref> PMID: 18334212 </ref>. As only OmpF is required, this may reveal how a general translocation route for a number of colicins may function<ref> PMID: 9687368 </ref>. However there is no evidence that this simply forms a pore for translocation, more work is needed to establish the translocation mechanism<ref> PMID: 17548346 </ref>. | ||
==Killing Activities== | ==Killing Activities== | ||
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| + | Colicin N depolarises the ''E. coli'' membrane, leading to lysis of the cell, and the cytotoxic domain that initiates this reaction is highly homologous to the C-terminal domain of ColA<ref> PMID: 2834623 </ref>. | ||
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| + | ==References== | ||
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| + | <references/> | ||
Revision as of 15:44, 11 February 2011
Colicin N is a type of Colicin, a bacteriocin made by E. coli which acts against other nearby E. coli to kill them by forming a pore in the membrane, leading to depolarisation of the membrane which kills the cell.
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Synthesis and release
The plasmid encoding the c. 42kDa[1] ColN also encodes its corresponding Colicin Immunity Protein, Cni, in order to protect the colicinergic cell from the cytotoxic activity of the colicin.
Mechanism of uptake
Colicin N parasitizes the outer membrane protein F (OmpF) as both its receptor and its translocator, alongside the Tol proteins TolQRA. There is evidence to show that the translocation may occur at the protein-lipid interface. ColN binding displaces OmpF-bound lipopolysaccharide, the major lipid in the outer leaflet of the outer membrane. The N terminal region of ColN then rearranges and binds to OmpF[2]. As only OmpF is required, this may reveal how a general translocation route for a number of colicins may function[3]. However there is no evidence that this simply forms a pore for translocation, more work is needed to establish the translocation mechanism[4].
Killing Activities
Colicin N depolarises the E. coli membrane, leading to lysis of the cell, and the cytotoxic domain that initiates this reaction is highly homologous to the C-terminal domain of ColA[5].
References
- ↑ Pugsley AP. Genetic analysis of ColN plasmid determinants for colicin production, release, and immunity. J Bacteriol. 1984 May;158(2):523-9. PMID:6327609
- ↑ Baboolal TG, Conroy MJ, Gill K, Ridley H, Visudtiphole V, Bullough PA, Lakey JH. Colicin N binds to the periphery of its receptor and translocator, outer membrane protein F. Structure. 2008 Mar;16(3):371-9. PMID:18334212 doi:10.1016/j.str.2007.12.023
- ↑ Vetter IR, Parker MW, Tucker AD, Lakey JH, Pattus F, Tsernoglou D. Crystal structure of a colicin N fragment suggests a model for toxicity. Structure. 1998 Jul 15;6(7):863-74. PMID:9687368
- ↑ Sharma O, Yamashita E, Zhalnina MV, Zakharov SD, Datsenko KA, Wanner BL, Cramer WA. Structure of the complex of the colicin E2 R-domain and its BtuB receptor. The outer membrane colicin translocon. J Biol Chem. 2007 Aug 10;282(32):23163-70. Epub 2007 Jun 4. PMID:17548346 doi:10.1074/jbc.M703004200
- ↑ Pugsley AP. Nucleotide sequencing of the structural gene for colicin N reveals homology between the catalytic, C-terminal domains of colicins A and N. Mol Microbiol. 1987 Nov;1(3):317-25. PMID:2834623
