Vectors for Cu2+‐inducible production of glutathione S‐transferase‐fusion proteins for single‐step purification from yeast

Abstract
We describe six new yeast episomal vectors which encode glutathione S‐transferase (GST) affinity tags. These allow for the production of GST‐fusion proteins in Saccharomyces cerevisiae under the control of the CUP1 promoter. Affinity chromatography with glutathione‐Sepharose permits convenient purification of the fusion protein from a yeast lysate. The presence of a protease cleavage site facilitates subsequent removal of the GST tag. The expression and single‐step purification of both GST and a functional GST‐metallothionein fusion from yeast are shown as an example of the application of these vectors.