EXPORT WITHOUT PROTEOLYTIC PROCESSING OF INNER AND OUTER-MEMBRANE PROTEINS ENCODED BY F-SEX FACTOR TRA CISTRONS IN ESCHERICHIA-COLI MINICELLS

Most tra proteins encoded by the E. coli F sex factor are incorporated into the minicell envelope. The authors have now assigned the tra proteins to cytoplasma (TraIp and 2b), inner membrane (TraEp, TraMp, and TraSp), and outer membrane (6e, TraAp, TraBp, TraJp, TraKp, TraLp, and TraTp). Two proteins, TraDp and 6d, were associated with both inner and outer membranes. The proteins exported to the inner or outer membranes did not undergo proteolytic cleavage (processing) whereas β-lactamase was processed normally.