A vector designed to include two tags wherein the first tag improves protein expression, folding and solubility, and the second tag promotes affinity purification, and two distinct recognition sequences for highly specific proteases. Uses of the vector include in vivo protein production.
 This invention was partially conceived under Contract No. W-31-109-ENG-38 between the U.S. Department of Energy and the University of Chicago representing Argonne National Laboratory. The U.S. Government may have certain rights in this invention.