Membrane Protein Insertion in E. coli

Integral membrane proteins typically span the lipid bilayer with hydrophobic α helices. These proteins can span the membrane once or multiple times with hydrophilic domains facing both sides of the membrane. In Escherichia coli , the insertion of proteins into the membrane is catalyzed by the Sec translocase and the YidC membrane insertase. YidC can function on its own to insert proteins or together with the Sec translocase to facilitate membrane protein insertion. In this chapter, we will describe the construction of a YidC depletion strain that can be used to examine whether YidC is required for membrane protein insertion. We will also present assays for determining whether a region of a membrane protein is inserted across the membrane.