Functions as a porin (PubMed:9928952). Induces apoptosis in human cell lines through caspase-dependent and AIF-dependent pathways. Purified Omp38 enters host cell and localizes to the mitochondria, which presumably leads to a release of proapoptotic molecules such as cytochrome c and AIF (apoptosis-inducing factor) (PubMed:16008580). Binds peptidoglycan, contributes to cell wall maintenance (Probable). Homotrimer (PubMed:9928952). Forms a pore with a size of 1.3 nm (PubMed:9928952). The periplasmic domain (residues 221-339) binds peptidoglycan (PGN) and diaminopimelate, one of the components of PGN. Significant loss of the bacterial outer membrane, not as able to induce apoptosis as wild-type bacteria in human cell lines. Live A.baumannii and purified Omp38 elicit identical effects with respect to the induction of apoptosis in human cell lines. Belongs to the outer membrane OOP (TC 1.B.6) superfamily.