Overexpressed protein with an N-terminal His tag has been reported not to hydrolyze glutathione; it is not clear if the construct is processed to 2 subunits (PubMed:14762019). an alpha-amino acid + an N-terminal (5-L-glutamyl)-[peptide] = 5-L-glutamyl amino acid + N-terminal L-alpha-aminoacyl-[peptide] glutathione + H2O = L-cysteinylglycine + L-glutamate an S-substituted glutathione + H2O = an S-substituted L-cysteinylglycine + L-glutamate This enzyme consists of two polypeptide chains, which are synthesized from a single polypeptide. Positively regulated by TnrA under nitrogen-limited conditions. Cleaved by autocatalysis into a large and a small subunit. Grows normally with glutathione as a sulfur source. Is not involved in the utilization of extracellular glutathione as a sulfur source. Belongs to the gamma-glutamyltransferase family.