Vectors for the inducible overexpression of glutathione S‐transferase fusion proteins in yeast

Abstract
A rapid and convenient method of protein purification involves creating a fusion protein with glutathione S‐transferase (GST) (Smith and Johnson, Gene 67, 31–40, 1988). In this report, we describe two vectors for the conditional expression of GST fusions in Saccharomyces cerevisiae. The parent plasmid is based on a high‐copy, galactose‐inducible shuttle vector previously described (Baldari et al., EMBO J. 6, 229–243, 1987). We have demonstrated the use of this system by creating fusions between GST and the yeast RAS2 gene. GST‐Ras2 fusion proteins undergo the post‐translational modifications required for Ras2p to become membrane localized. These vectors provide a useful system for the expression an dpurification of eukaryotic proteins requiring post‐translational modification.