Colicin, receptor domain (IPR024566)

Short name: Colicin_R_dom

Overlapping homologous superfamilies


Domain relationships



Bacteriocins are protein antibiotics that kill bacteria closely related to the producing species. Colicins are a subgroup of bacteriocins that are produced by and target Escherichia coli. The lethal action of most colicins is exerted either by formation of a pore in the cytoplasmic membrane of the target cell, or by an enzymatic nuclease digestion mechanism.

Most colicins are able to translocate the outer membrane by a two-receptor system, where one receptor is used for the initial binding and the second for translocation. The initial binding is to cell surface receptors such as the porins OmpF, FepA, BtuB, Cir and FhuA. The presence of specific periplasmic proteins, such as TolA, TolB, TolC, or TonB, are required for translocation across the membrane [PMID: 12423783].

Colicins are composed of domains with distinct functional roles. In general they contain a central R (receptor) domain that mediates receptor binding, an N-terminal T (translocation) domain that mediates translocation of the protein from the outer membrane receptor to the colicin's target within the cell, and a C-terminal C (catalytic) domain that performs the catalytic cleavage [PMID: 12409205].

This entry represents the central R domain found in colicin-E2 and other colicins.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.