Antigen peptide transporter 2 (IPR005293)

Short name: Tap2/ABCB3

Overlapping homologous superfamilies

Family relationships


The ABC transporter family is a group of membrane proteins that use the hydrolysis of ATP to power the translocation of a wide variety of substrates across cellular membranes. ABC transporters minimally consist of two conserved regions: a highly conserved nucleotide-binding domain (NBD) and a less conserved transmembrane domain (TMD). Eukaryotic ABC proteins are usually organised either as full transporters (containing two NBDs and two TMDs), or as half transporters (containing one NBD and one TMD), that have to form homo- or heterodimers in order to constitute a functional protein [PMID: 11441126].

This entry represents Tap2 (also known as antigen peptide transporter 2), which is an eukaryotic protein belonging to the ABC transporter family. It plays a crucial role in the processing and presentation of the MHC class I-restricted antigens. It is a half transporter that forms a complex with Tap1. This complex translocates antigens from the cytoplasm to the endoplasmic reticulum for loading onto MHC class I molecules [PMID: 21205905].

GO terms

Biological Process

GO:0019885 antigen processing and presentation of endogenous peptide antigen via MHC class I

Molecular Function

GO:0005524 ATP binding
GO:0042287 MHC protein binding
GO:0015440 peptide-transporting ATPase activity

Cellular Component

GO:0042825 TAP complex
GO:0030176 integral component of endoplasmic reticulum membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.