THE ROLE OF PHOSPHOLIPID ENVIRONMENT IN THE MEMBRANE PROTEIN TRANSLOCATION IN E.COLI
Membrane proteins fulfill a number of important functions in the cells, including energetic, signaling and transport functions. Translocation and insertion of membrane proteins of E.coli utilize such membrane complexes as SecYEG and Tat-translocon, performing co-translational or post-translational folding. Phospholipids form an environment leading to correct membrane folding and final topology. Phospholipids may affect both on the translocation system interacting with synthesized polypeptide chain or with folded protein and directly on protein folding, being a lipochaperones. Interaction of phospholipids with membrane proteins has dynamic behavior that determines possibility to orientate protein structure in the different directions relatively to the membrane. Apparently, proteins with dual-topology may have biological meaning. The mechanisms of lipid and proteins interactions are discussed.