Escherichia coli expression vectors containing a protein kinase recognition motif, His6-tag and hemagglutinin epitope

Escherichia coli expression vectors, based on the pET system, were constructed to allow fusion of a protein kinase (PK) recognition motif, a hemagglutinin (HG) epitope-tag and a His6-tag at the N-terminal portion of a protein of interest. The fusion proteins, that result from expression using these vectors, can be phosphorylated in vitro using cAMP-dependent PK, immunoprecipitated using monoclonal antibody against the HG-epitope, and can be rapidly purified using a Ni2+ column.