3F8U

Tapasin/ERp57 heterodimer

Summary for 3F8U

• Entry DOI: 10.2210/pdb3f8u/pdb
• Descriptor: Protein disulfide-isomerase A3ERp57, Tapasin, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: endoplasmic reticulum, glycoprotein, immunoglobulin domain, membrane, microsome, protein disulfide isomerase, thioredoxin-like fold, ig-like domain, beta barrel, isomerase, redox-active cente, immune system-isomerase complex, immune system/isomerase
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 4
• Total formula weight: 194628.14

Authors

Dong, G.,Reinisch, K.M. (deposition date: 2008-11-13, release date: 2009-01-13, Last modification date: 2024-10-30)

Primary citation

Dong, G.,Wearsch, P.A.,Peaper, D.R.,Cresswell, P.,Reinisch, K.M.
Insights into MHC class I peptide loading from the structure of the tapasin-ERp57 thiol oxidoreductase heterodimer.
Immunity, 30:21-32, 2009

PubMed Abstract: Tapasin is a glycoprotein critical for loading major histocompatibility complex (MHC) class I molecules with high-affinity peptides. It functions within the multimeric peptide-loading complex (PLC) as a disulfide-linked, stable heterodimer with the thiol oxidoreductase ERp57, and this covalent interaction is required to support optimal PLC activity. Here, we present the 2.6 A resolution structure of the tapasin-ERp57 core of the PLC. The structure revealed that tapasin interacts with both ERp57 catalytic domains, accounting for the stability of the heterodimer, and provided an example of a protein disulfide isomerase family member interacting with substrate. Mutational analysis identified a conserved surface on tapasin that interacted with MHC class I molecules and was critical for peptide loading and editing functions of the tapasin-ERp57 heterodimer. By combining the tapasin-ERp57 structure with those of other defined PLC components, we present a molecular model that illuminates the processes involved in MHC class I peptide loading.

PubMed: 19119025
DOI: 10.1016/j.immuni.2008.10.018

Experimental method

X-RAY DIFFRACTION (2.6 Å)