Colicin E9: Difference between revisions

The endonuclease domain of colicin E9 is able to form ion channels in planar lipid bilayers. The E9 DNase mediates its own translocation across the cytoplasmic membrane, and the formation of ion channels is essential to this process. The association of colicin E9 with negative phospholipids results in a destabilisation of the DNase. This is protected by the colE9 immunity protein, [[Im9]], but not by the binding of zinc to the active site. Formation of this destabilising complex preempts channel formation by the DNase, and makes up the first step in the translocation of colE9 across the ''E. coli'' inner membrane. The channels are then assumed to reseal themselves once the cytotoxic domain of the colicin has entered the cytoplasm.