The translocation of LPS from the inner membrane IM to the outer membrane OM is unidirectional . All components of LPS (lipid A, core, and O antigen) are synthesized on the internal lobules of IM, where lipid A and core are connected to form the so-called rough LPS. The rough LPS and O antigens pass through the IM independently and are ligated on the lobules of the IM . Then LPS is extracted from IM by ABC transporter.