H2-Dd with peptide editor TAPBPR at 3.41Å resolution
Data provenance
Information sections
Complex type
H2-Dd
Species
Locus / Allele group
Crystal structure of a TAPBPR-MHC-I complex reveals the mechanism of peptide editing in antigen presentation.
Central to CD8+ T cell-mediated immunity is the recognition of peptide-major histocompatibility complex class I (p-MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined. We report the crystal structure of MHC I in complex with the peptide editor TAPBPR (TAP-binding protein-related), a tapasin homolog. TAPBPR remodels the peptide-binding groove of MHC I, resulting in the release of low-affinity peptide. Changes include groove relaxation, modifications of key binding pockets, and domain adjustments. This structure captures a peptide-receptive state of MHC I and provides insights into the mechanism of peptide editing by TAPBPR and, by analogy, tapasin.
Structure deposition and release
Data provenance
Publication data retrieved from PDBe REST API8 and PMCe REST API9
Other structures from this publication
A Pocket
TYR159
GLU163
TRP167
TYR171
LEU5
TYR59
GLU63
ARG66
TYR7
|
B Pocket
GLU24
VAL34
TYR45
GLU63
ARG66
ALA67
TYR7
ASN70
VAL9
ALA99
|
C Pocket
ASN70
CYS73
PHE74
VAL9
TRP97
|
D Pocket
TRP114
ARG155
ASP156
TYR159
LEU160
ALA99
|
E Pocket
TRP114
TRP147
ALA152
ASP156
TRP97
|
F Pocket
PHE116
TYR123
THR143
LYS146
TRP147
ASP77
THR80
ALA81
TYR84
LEU95
|
Colour key
Data provenance
1. Beta 2 microglobulin
Beta 2 microglobulin
|
10 20 30 40 50 60
MIQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKD 70 80 90 WSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM |
2. Class I alpha
H2-Dd
|
10 20 30 40 50 60
MSHSLRYFVTAVSRPGFGEPRYMEVGYVDNTEFVRFDSDAENPRYEPRARWIEQEGPEYW 70 80 90 100 110 120 ERETRRAKGNEQCFRVDLRTALRYYNQSAGGSHTLQWMAGCDVESDGRLLRGYWQFAYDG 130 140 150 160 170 180 CDYIALNEDLKTWTAADMAAQITRRKWEQAGAAERDRAYLEGECVEWLRRYLKNGNATLL 190 200 210 220 230 240 RTDPPKAHVTHHRRPEGDVTLRCWALGFYPADITLTWQLNGEELTQEMELVETRPAGDGT 250 260 270 FQKWASVVVPLGKEQKYTCHVEHEGLPEPLTLRWGKE |
3. TAPBPR (Tapasin homologue)
TAPBPR (Tapasin homologue)
|
10 20 30 40 50 60
KPHPAEGQWRAVDVVLDCFLVKDGAHRGALASSEDRARASLVLKQVPVLDDGSLEDFTDF 70 80 90 100 110 120 QGGTLAQDDPPIIFEASVDLVQIPQAEALLHADCSGKEVTCEISRYFLQMTETTVKTAAW 130 140 150 160 170 180 FMANVQVSGGGPSISLVMKTPRVAKNEVLWHPTLNLPLSPQGTVRTAVEFQVMTQTQSLS 190 200 210 220 230 240 FLLGSSASLDCGFSMAPGLDLISVEWRLQHKGRGQLVYSWTAGQGQAVRKGATLEPAQLG 250 260 270 280 290 300 MARDASLTLPGLTIQDEGTYICQITTSLYRAQQIIQLNIQASPKVRLSLANEALLPTLIC 310 320 330 340 350 360 DIAGYYPLDVVVTWTREELGGSPAQVSGASFSSLRQSVAGTYSISSSLTAEPGSAGATYT 370 380 390 CQVTHISLEEPLGASTQVVPPERRLEGGLEVLFQ |
Data provenance
Sequences are retrieved via the Uniprot method of the RSCB REST API. Sequences are then compared to those derived from the PDB file and matched against sequences retrieved from the IPD-IMGT/HLA database for human sequences, or the IPD-MHC database for other species. Mouse sequences are matched against FASTA files from Uniprot. Sequences for the mature extracellular protein (signal petide and cytoplasmic tail removed) are compared to identical length sequences from the datasources mentioned before using either exact matching or Levenshtein distance based matching.
Downloadable data
Complete structures
Components
Data license
Footnotes
- Protein Data Bank Europe - Coordinate Server
- 1HHK - HLA-A*02:01 binding LLFGYPVYV at 2.5Å resolution - PDB entry for 1HHK
- Protein structure alignment by incremental combinatorial extension (CE) of the optimal path. - PyMol CEALIGN Method - Publication
- PyMol - PyMol.org/pymol
- Levenshtein distance - Wikipedia entry
- Protein Data Bank Europe REST API - Molecules endpoint
- 3Dmol.js: molecular visualization with WebGL - 3DMol.js - Publication
- Protein Data Bank Europe REST API - Publication endpoint
- PubMed Central Europe REST API - Articles endpoint
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