Tripeptidyl peptidase II (TPPII) is a crucial component of the proteolytic cascade acting downstream of the 26S proteasome in the ubiquitin-proteasome pathway. It is an amino peptidase belonging to the subtilase family removing tripeptides from the free N terminus of oligopeptides. This protein adopts a dimeric assembly. Each monomer is organised into three main parts: the N-terminal subtilisine-like domain (Pfam:PF00082) a central domain and C-terminal domain (Pfam:PF12583). The central domain can be subdivided into two Ig-like domains and a GBD-like domain (Pfam:PF21316). This entry represents the first Ig-like domain, while Pfam:PF12580 represents the second one [1].

1: Hybrid molecular structure of the giant protease tripeptidyl peptidase II. Chuang CK, Rockel B, Seyit G, Walian PJ, Schonegge AM, Peters J, Zwart PH, Baumeister W, Jap BK; Nat Struct Mol Biol. 2010;17:990-996. PMID:20676100