Identification of an Ancillary Protein, YabF, Required for Activity of the KefC Glutathione-Gated Potassium Efflux System in <i>Escherichia coli</i>

Abstract

A new subunit, YabF, for the KefC K(+) efflux system in Escherichia coli has been identified. The subunit is required for maximum activity of KefC. Deletion of yabF reduces KefC activity 10-fold, and supply of YabF in trans restores activity. IS2 and IS10R insertions in yabF can be isolated as suppressors of KefC activity consequent upon the V427A and D264A KefC mutations.