To flip or not to flip: lipid-protein charge interactions are a determinant of final membrane protein topology.

ABSTRACT: The molecular details of how lipids influence final topological organization of membrane proteins are not well understood. Here, we present evidence that final topology is influenced by lipid-protein interactions most likely outside of the translocon. The N-terminal half of Escherichia coli lactose permease (LacY) is inverted with respect to the C-terminal half and the membrane bilayer when assembled in mutants lacking phosphatidylethanolamine and containing only negatively charged phospholipids. We demonstrate that inversion is dependent on interactions between the net charge of the cytoplasmic surface of the N-terminal bundle and the negative charge density of the membrane bilayer surface. A transmembrane domain, acting as a molecular hinge between the two halves of the protein, must als

SUBMITTER: Bogdanov M 

PROVIDER: S-EPMC2528571 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature