oligopeptide fragment oligopeptide fragment (8-16aa) Transport of Antigen peptide in to ER Authored: Garapati, P V, 2010-10-29 Edited: Garapati, P V, 2010-10-29 Pubmed10600378 Pubmed12645939 Pubmed19261456 Pubmed8342042 Reactome Database ID Release 43983144 Reactome, http://www.reactome.org ReactomeREACT_75812 Reviewed: Elliott, T, 2011-02-10 Ttransporter associated with antigen processing (TAP) is a heterodimeric complex, composed of TAP1 and TAP2 proteins, members of the ATP-binding cassette (ABC) superfamily. TAP consists of two transmembrane domains (TMDs) and two cytosolic nucleotide-binding domains. Peptide binding to the cytosolic-facing cavity formed by the TMDs causes it to undergo a conformational change that induces ATP hydrolysis, forcing the opening of a pore and translocation of the peptide into the ER lumen. TAP transports peptides in the range of 8-16 amino acids into the ER, which is the peptide length typically generated by the immunoproteasome. has a Stoichiometric coefficient of 2