Component of the GSH degradosomal complex involved in the degradation of glutathione (GSH) and other peptides containing a gamma-glu-X bond. Binds 2 Zn(2+) ions per subunit. Component of the GSH degradosomal complex composed of at least DUG1, DUG2 and DUG3. Present with 1940 molecules/cell in log phase SD medium. Belongs to the peptidase M20A family.