E.coli mutants in the upper part of their E protein such as LolCDE(D264A), Lol CDE(I268D), LolCDE(Y366A) and LolCDE(F367D) reduced lipoprotein binding and were lethal . In contrast, other mutants surrounding the lipoprotein triacyl chains in the protein C like LolC(M48G)DE, LolC(M267E)DE or LolC(L356D)DE, were not lethal. Mutants in the D proteins caused disintegration of the LolCDE complex. The results of all these studies, suggest that the peptide moieties of lipoproteins mostly interact with the E protein at the LolCDE complexes and that the lipoprotein peptide-binding residues at the upper part of E, may be essential for LolCDE transport. The mutational studies and the crystal structures briefly commented above, clarified E.coli lipoprotein transport mechanisms and allowed an hypothetical probable modeling of the A. baumannii LolCE. Accordingly, the upper α-helices of the E protein modeled in the A. baumannii LolCE heterodimer have been targeted here to study abaucin-derivatives.