Lol complexes involve 3-5 different proteins depending on the lipoprotein transport stages . E.coli LolCDE consists of a CE protein heterodimer inserted in the bacterial membranes through C4+E4 transmembrane α-helices and projecting outside their head and cytosolic domains. With a sequence identity of only 14.6 %, C and E proteins form dimerization interfaces with C2+E2 α-helical V shaped central lipoprotein-binding cavity extending above ~20 Å out the bacterial membranes. The LolCE complex is maintained together by a DD homodimer interacting with the cytosolic domains down the membrane. Purified E.coli LolCDE revealed a number of lipoprotein ligands. Most ligands contain one 9-10 amino acid peptide upwards linked to three downward hydrophobic triacyl chains. The other LolC2+E2 α-helices, sterically prevent any possible scape of the bound lipoproteins (Figure ). The DD dimer shows ATP-binding capacities implicating ATP hydrolysis in LolCE open/close conformational changes. Protein A binds above C and also participate in the conformational changes (RMSD 3.6-4.8 Å). Conformational changes facilitate ATP hydrolysis, inner to outer membrane transport and delivery of the lipoprotein .