Low Resolution Structure and Dynamics of a Colicin-Receptor Complex Determined by Neutron Scattering

摘要: Proteins that translocate across cell membranes need to overcome a significant hydrophobic barrier. This is usually accomplished via specialized protein complexes, which provide polar transmembrane pore. Exceptions this include bacterial toxins, insert into and cross the lipid bilayer itself. We are studying mechanism by large antibacterial proteins enter Escherichia coli specific outer membrane proteins. Here we describe use of neutron scattering investigate interaction colicin N with its receptor OmpF. The positions lipids, N, OmpF were separately resolved within complex structures selective deuteration. Neutron reflectivity showed, in real time, mediates insertion monolayers. data complemented Brewster Angle Microscopy images, showed lateral association presence N. Small angle experiments then defined three-dimensional structure N-OmpF complex. revealed unfolds binds OmpF-lipid interface. implications unfolding step for translocation discussed.