Peptidoglycan-recognition protein that plays a key role in innate immunity by binding to peptidoglycans (PGN) of Gram-positive bacteria and activating the Toll pathway. Has no activity against on Gram-negative bacteria and fungi. Shows some partial redundancy with PRPGP-SA in Gram-positive bacteria recognition. May act by activating the proteolytic cleavage of Spatzle and the subsequent activation of Toll pathway. Recognizes S.aureus PGN. In larvae, it is mainly expressed in fat body. Also expressed in uninduced hemocytes and mbn-2 cells. Expressed from old embryos. Expressed in larvae and adults. Strongly up-regulated by PGN from B.subtilis. Weakly or not expressed in normal conditions. Regulated by the imd/Relish pathway. Belongs to the N-acetylmuramoyl-L-alanine amidase 2 family.