NAALADL2 (N­acetylated alpha­linked acidic dipeptidase like 2) is a member of the peptidase M28 family of enzymes. It is presumably a type II transmembrane (TM) protein that may have O­glycosyl hydrolase activity. Human NAALADL2 is 795 amino acids (aa) in length. It is believed to contain a cytoplasmic and TM segment at the N­terminus, followed by a peptidase domain (aa444­596) and a TfR­like dimerization region (aa688­777). There are multiple splice forms. One shows a 4aa substitution for aa292­795, a second shows an alternate start site at aa18 with a 24aa substitution for aa314­795, and a third contains an alternate start site at aa283, accompanied by a deletion of aa363­411 and 633­795. Over aa152­795, human NAALADL2 shares 87% and 82% aa sequence identity with mouse and canine NAALADL2, respectively.