Colicin V is a small, proteinaceous bacterial toxin, produced by many strai
ns of Escherichia coli and other members of the Enterobacteriaceae, that fi
ts the definition of class II bacteriocins of Grampositive bacteria. Export
of colicin V is dependent on specific ABC (ATP-binding cassette) secretion
proteins which recognize a double-glycine-type leader peptide on the immat
ure colicin V bacteriocin. Replacement of the colicin V leader peptide by a
signal peptide from the signal sequence-dependent bacteriocin divergicin A
allowed expression of colicin V in lactic acid bacteria. This system may s
erve as a model for the heterologous expression of other small bacteriocins
active against Gram-negative bacteria and other antibacterial peptides fro
m lactic acid bacteria.