Among the living organisms, Escherichia coli has been the most common choice employed for recombinant protein expression. In addition to its well-characterized genetics, E. coli is fast growing, relatively cheap, and easy to handle. These fine properties, in conjunction with the success achieved in transforming plasmid DNA into E. coli, as well as the advent of various genetic engineering techniques in the 1970s, have enabled E. coli to be considered as the most favorable host for genetic manipulations. The recent advances in better comprehension of regulatory controls of gene expression and the availability of various novel approaches, which include both intracellular, e.g., through intein-mediated expression and self-cleavages, and extracellular, e.g., through the use of secretion signals, to achieve successful expression of the target proteins in E. coli further support the view that E. coli is the most promising host choice for heterologous protein expression.
Part of the book: The Universe of Escherichia coli