ABI may interact with a target in the cell membrane, which could be the product of the host's cmrA gene, and cause disruption of the cellular membrane such that lysis of the infected cell and death of the infecting phage would result. This very hydrophobic protein could insert itself into membranes. When phage T5 or its close relative BF23, infects cells harboring a ColIb plasmid, the infection is abortive. The mechanism involves gene products from the phage, the ColIb plasmid, and the host.