Recent developments in heterologous protein production in Escherichia coli.

During the past three to four years, remarkable progress has been made in our understanding of protein folding, protein translocation across biological membranes, and the role of molecular chaperones in these processes. In conjunction with recent developments in Escherichia coli expression systems, this understanding has led to an improved capability to accumulate proteins in a soluble form, secrete proteins from the cell cytoplasm, accumulate proteins in the cytoplasmic membrane, and direct proteins to the outer membrane of the cell for surface display. These advances suggest that E. coli should now be considered seriously for applications that, only a few years ago, would have been thought beyond the scope of this organism.