Escherichia coli outer membrane protein tolC is involved in production of the peptide antibiotic microcin J25

Abstract

A Tn5 insertion in tolc eliminated microcin J25 production. The mutation had little effect on the expression of the microcin structural gene and presumably acted by blocking microcin secretion. The tolC mutants carrying multiple copies of the microcin genes were less immune to the microcin. TolC is thus likely a component of a microcin export complex containing the McjD immunity protein, an ABC exporter.