Site-directed mutagenesis of the Proteus mirabilis glutathione transferase B1-1 G-site

In order to investigate the roles of near N-terminus Tyr, Cys, and Ser residues in the activity of bacterial glutathione transferase (GSTB1-1) site-directed mutagenesis was used to replace the following residues: Tyr-4, Tyr-5, Ser-9, Cys-10, Ser-11, and Ser-13. The results presented here show that, unlike all other alpha, mu, pi, theta and sigma classes of glutathione transferases so far investigated, GSTB1-1 does not utilise any Tyr, Ser or Cys residue to activate glutathione. These results also suggest that the bacterial glutathione transferases may require classification into their own class.