Extracellular production of recombinant proteins using bacterial autotransporters

Escherichia coli is still a very popular host for the production of recombinant proteins at an analytical or industrial scale. Secretion of the proteins into the culture medium or display at the cell surface would be preferred in many applications but is hampered by the complex two-layered cell envelope. The autotransporter pathway is used by E. coli to secrete virulence factors via a relatively simple but efficient and specific mechanism. Here we discuss recent progress in the structural and mechanistic analysis of this pathway and the implications for future development of a versatile platform for secretion and display of heterologous proteins.