Cleaves, in an endo-type manner, the gamma-glutamyl bond between D-glutamate and L-glutamate of poly-gamma-glutamate (PGA). Inhibited by pretreatment with 1 mM 4-(hydroxymercuri)benzoate, a sulfhydryl inhibitor. Optimum pH is 5.0. Optimum temperature is 45 degrees Celsius. Cell wall localization shown in PubMed:11987133. In stationary phase; under control of SigD. Belongs to the peptidase C40 family.