Novel vectors for co-expression of two proteins in E. coli.

Two new vectors, pAC28 and pEGST, for the co-expression of recombinant genes in E. coli were developed. This two-plasmid system allows for an efficient expression and purification of large amounts of protein-protein complexes formed in bacterial cells. We have utilized this new system to express and isolate a stable complex of two human proteins, hematopoietic cell tyrosine phosphatase (HePTP) and mitogen-activated proteins kinase Erk2. This approach is useful for biochemical and structural studies of protein-protein interactions.