Biological membranes envelope the cells of all organisms and growth and division of cells requires constant addition of new protein and lipid constituents to the membranes. We will determine the mechanism by which protein and lipid molecules are inserted into an essential membrane of bacterial cells. Recent technological advances now make this a feasible undertaking. Completion of the project will provide understanding of how the bacterial outer membrane is built from its component parts, and what can be done to manipulate the process. Expected outcomes are detailed knowledge of the mechanism of membrane assembly, and how this process is regulated in bacteria.