Amino acid alterations in a hydrophobic region of the TraT protein of R6-5 increase the outer membrane permeability of enteric bacteria.

Two insertion mutations, each introducing a new negatively charged amino acid residue into a hydrophobic region of the TraT protein coded by the F-like plasmid R6-5 caused significant alterations in outer membrane permeability of Escherichia coli and Salmonella typhimurium, so that strains carrying plasmids with either of these mutations became sensitive to hydrophobic antibiotics.