The distribution of homologues of the Escherichia coli KefC K(+)-efflux system in other bacterial species.

Using a variety of techniques the distribution of the glutathione-regulated KefC K(+)-transport system among bacterial species was investigated. The presence of similar systems in a number of Gram-negative bacteria was demonstrated. In contrast, the system appeared to be absent from most Gram-positive bacteria tested with the exception of Staphylococcus aureus. Using the cloned Escherichia coli kefC gene as a probe for Southern hybridization it was shown that only limited DNA sequence homology exists with other bacteria, even when closely related members of the enteric group were examined.