tolQ is required for cloacin DF13 susceptibility in Escherichia coli expressing the aerobactin/cloacin DF13 receptor IutA

We investigated the role of the tolQ gene in the import of cloacin DF13 across the outer membrane of Escherichia coli strains expressing the IutA receptor. The IutA outer-membrane protein is the receptor for the siderophore ferric aerobactin and also binds cloacin DF13, a bacteriocin produced by strains of Enterobacter aerogenes. In this report we present evidence that tolQ is required for the internalization of cloacin DF13 upon binding to IutA but it is not involved in the transport of ferric aerobactin.