Colicin

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spinqualitylabelsall models PDB ID 2k5x Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
2k5x, 1 NMR models ()
Gene:	imm, ceiE9 (Escherichia coli), col, cei (Escherichia coli)
Related:	1imq, 1fsj, 1emv
Structural annotation: Resources: InterPro : Ipr000290, Ipr003058, Ipr016128, Ipr003615 Pfam : PF01320
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

Colicins are a type of bacteriocin - peptide and protein antibiotics released by bacteria to kill other bacteria of the same species. Bacteriocins are named after their species of origin; colicins are so-called because they are produced by E. Coli^[1]. Because of their narrow killing spectrum which focuses primarily on the species which has made the peptide, bacteriocins are important in microbial biodiversity and the stable co-existence of the bacterial populations.

Colicin peptides are plasmid-encoded. The peptide is released by the cell into the area surrounding it, and then parasitises proteins present in the host cell membrane to translocate across into the host cell. Many protein-protein interactions are involved in the cell entry, and the main system is involved in the grouping of colicins into two families: Group A colicins use the Tol system to enter the host cell, and Group B use the Ton system. Once inside the host cell, the cell killing follows 1st order kinetics - ie one molecule is theoretically sufficient to kill the cell.

The structure of all colicins, of which over 20 have been identified, follows a 3 domain design:
At the N terminus is the Translocation domain (T-)
The Receptor binding domain is at the centre of the peptide (R-)
The C terminus contains the Cytotoxic domain (C-).

Contents 1 Synthesis and Production 2 Release 3 Targeting and Receptors 4 Colicin Uptake 5 Killing Activities 6 References

Synthesis and Production

Release

Targeting and Receptors

Colicin Uptake

Killing Activities

List of colicins, with their translocation proteins and cytotoxic activity

Colicin	Group	OM Receptor	Translocation Proteins	Cytotoxic activity
Colicin A	A	BtuB	OmpF/TolQRAB	Pore-forming
Colicin E1	A	BtuB	TolC/TolAQ	Pore-forming
Colicin E2	A	BtuB	OmpF/TolQRAB	DNase
Colicin E3	A	BtuB	OmpF/TolQRAB	16s rRNase
Colicin E4	A	BtuB	OmpF/TolQRAB	16s rRNase
Col E5	A	BtuB	OmpF/TolQRAB	tRNase
Col E6	A	BtuB	OmpF/TolQRAB	16s rRNase
Col E7	A	BtuB	OmpF/TolQRAB	DNase
Col E8	A	BtuB	OmpF/TolQRAB	DNase
Col E9	A	BtuB	OmpF/TolQRAB	DNase
Col N	A	OmpF	OmpF/TolQRA	Pore-forming
Col S4	A	OmpW	OmpF/TolQRAB	Pore-forming
Col K	A	Tsx	OmpF/TolQRAB	Pore-forming
Cloacin DF 13	A	lutA [2]	TolQRA [3]	16s rRNase [4]
Col U	A	?	OmpAF, TolQRAB	Pore-forming
Col 5	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col 6	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col 7	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col 8	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col 9	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col 10	B	Tsx	TolC/TonB, ExbBD	Pore-forming
Col-la	B	Cir	Cir/TonB, ExbBD	Pore-forming
Col-lb	B	Cir	Cir/TonB, ExbBD	Pore-forming
Col B	B	FepA	?/TonB, ExbBD	Pore-forming
Col D	B	FepA	?/TonB, ExbBD	tRNase
Col M	B	FhuA	?/TonB, ExbBD	Inhibition of PG synthesis
Col V	B	Cir? [5]	TonB, ExbB	Disruption of membrane potential
Col Js	B	CjrBC	ExbBD, VirB	?
Col Y	?	?	?	Pore-forming [6]

Table taken from ^[7] except where indicated.

References

1. ↑ Cascales E, Buchanan SK, Duche D, Kleanthous C, Lloubes R, Postle K, Riley M, Slatin S, Cavard D. Colicin biology. Microbiol Mol Biol Rev. 2007 Mar;71(1):158-229. PMID:17347522 doi:10.1128/MMBR.00036-06
2. ↑ Wooldridge KG, Williams PH. Sensitivity of Escherichia coli to cloacin DF13 involves the major outer membrane protein OmpF. J Bacteriol. 1991 Apr;173(8):2420-4. PMID:2013565
3. ↑ Thomas JA, Valvano MA. Role of tol genes in cloacin DF13 susceptibility of Escherichia coli K-12 strains expressing the cloacin DF13-aerobactin receptor IutA. J Bacteriol. 1993 Jan;175(2):548-52. PMID:8419302
4. ↑ Baan RA, Duijfjes JJ, van Leerdam E, van Knippenberg PH, Bosch L. Specific in situ cleavage of 16S ribosomal RNA of Escherichia coli interferes with the function of initiation factor IF-1. Proc Natl Acad Sci U S A. 1976 Mar;73(3):702-6. PMID:768982
5. ↑ Waters VL, Crosa JH. Colicin V virulence plasmids. Microbiol Rev. 1991 Sep;55(3):437-50. PMID:1943995
6. ↑ Riley MA, Cadavid L, Collett MS, Neely MN, Adams MD, Phillips CM, Neel JV, Friedman D. The newly characterized colicin Y provides evidence of positive selection in pore-former colicin diversification. Microbiology. 2000 Jul;146 ( Pt 7):1671-7. PMID:10878131
7. ↑ Kleanthous C. Swimming against the tide: progress and challenges in our understanding of colicin translocation. Nat Rev Microbiol. 2010 Dec;8(12):843-8. Epub 2010 Nov 9. PMID:21060316 doi:10.1038/nrmicro2454