BACTERIOCIN 28B FROM SERRATIA-MARCESCENS N28B - IDENTIFICATION OF ESCHERICHIA-COLI SURFACE COMPONENTS INVOLVED IN BACTERIOCIN BINDING AND TRANSLOCATION

Serratia marcescens N28b produces bacteriocin 28b, active against Esch erichia coli. Bacteriocin sensitivity tests performed on a collection of E. coli envelope mutants, and isolation and characterization of E. coli bacteriocin-28b-insensitive mutants, showed that the core lipopol ysaccharide, outer membrane proteins OmpA and OmpF, and To1Q, To1A, an d To1B proteins are involved in bacteriocin 28b lethal activity. These mutants were assayed for bacteriocin 28b sensitivity under normal and bypass conditions, and their bacteriocin-binding ability was determin ed. The results obtained suggest that the core lipopolysaccaride and o uter membrane proteins OmpA and OmpF are involved in bacteriocin 28b b inding. Furthermore,bacteriocin 28b translocation requires proteins To 1A, To1B, and To1Q.