Membrane proteins play critical roles in diverse cellular processes such as energy conversion, cellular transport, signal transduction and cell division. Many bacterial inner membrane proteins are co-translationally inserted into the membrane, in most cases by the well-studied Sec pathway using signal recognition particle and the SecYEG protein insertion channel. The more recently discovered YidC/Oxa1 membrane protein insertion system represents an alternative to the canonical Sec Pathway. How do the protein insertion mechanisms compare? How are the two insertion systems connected? The Author Rebecca Kohler presents an introductory overview of co-translational membrane protein insertion and discusses the characteristics of the Sec and YidC/Oxa1 insertion systems. A structural and functional study of the YidC/Oxa1 system forms the basis for the following analysis. This book addresses researchers and students in life sciences as well as scientific employees in the biotech industry.