Enterocin P is a bacteriocin produced by Enterococcus faecium P13, We studi
ed the mechanism of its bactericidal action using enterocin-P-sensitive E,
faecium T136 cells. The bacteriocin is incapable of dissipating the transme
mbrane pH gradient. On the other hand, depending on the buffer used, entero
cin P dissipates the transmembrane potential. Enterocin P efficiently elici
ts efflux of potassium ions, but not of intracellularly accumulated anions
like phosphate and glutamate, Taken together, these data demonstrate that e
nterocin P forms specific, potassium ion-conducting pores in the cytoplasmi
c membrane of target cells.