Expression and Secretion of Foreign Proteins in Escherichia Coli

This chapter discusses the development of a set of expression and secretion vectors designed to overcome several of the problems encountered when expressing a given gene in Escherichia coli. These vectors have been designed for use at specific steps during the cloning and expression of proteins as well as for the particular needs that might come with the nature of the protein to be produced, such as the necessity to secrete products that are toxic for cell growth. The chapter discusses the different vectors that are constructed and the way they can best be utilized for cloning, expression, and secretion. The first step in achieving expression of a protein is to clone the DNA fragment in generalized expression vectors. The chapter discusses the utilization of the pIN-H and pIN-III expression vector, secretion vectors in E. coli, and pIN-III-OmpA secretion vectors. As β-lactamase is an E. coli protein normally secreted into the periplasmic space, pIN-III-OmpA was tested for the production and secretion of an extracellular protein from gram-positive bacteria.