H2-Kb presenting "SIYRYYGL" to Alpha/Beta T cell receptor at 2.80Å resolution
Data provenance
Information sections
- Publication
- Peptide details
- Peptide neighbours
- Binding cleft pockets
- Chain sequences
- Downloadable data
- Data license
- Footnotes
Complex type
Class i with peptide and alpha beta tcr
H2-Kb
SIYRYYGL
TRAV9
TRBV13
Species
Locus / Allele group
A functional hot spot for antigen recognition in a superagonist TCR/MHC complex.
A longstanding question in T cell receptor signaling is how structurally similar ligands, with similar affinities, can have substantially different biological activity. The crystal structure of the 2C TCR complex of H-2Kb with superagonist peptide SIYR at 2.8 A elucidates a structural basis for TCR discrimination of altered peptide ligands. The difference in antigen potency is modulated by two cavities in the TCR combining site, formed mainly by CDRs 3alpha, 3beta, and 1beta, that complement centrally located peptide residues. This "functional hot spot" allows the TCR to finely discriminate amongst energetically similar interactions within different ligands for those in which the peptide appropriately stabilizes the TCR/pMHC complex and provides a new structural perspective for understanding differential signaling resulting from T cell cross-reactivity.
Structure deposition and release
Data provenance
Publication data retrieved from PDBe REST API8 and PMCe REST API9
Other structures from this publication
Data provenance
MHC:peptide complexes are visualised using PyMol. The peptide is superimposed on a consistent cutaway slice of the MHC binding cleft (displayed as a grey mesh) which best indicates the binding pockets for the P1/P5/PC positions (side view - pockets A, E, F) and for the P2/P3/PC-2 positions (top view - pockets B, C, D). In some cases peptides will use a different pocket for a specific peptide position (atypical anchoring). On some structures the peptide may appear to sterically clash with a pocket. This is an artefact of picking a standardised slice of the cleft and overlaying the peptide.
Peptide neighbours
P1
SER
LEU5
TYR59
TYR159
TYR7
LYS66
TYR171
TRP167
GLU63
ARG62
|
P2
ILE
GLU63
TYR45
ASN70
TYR159
TYR7
LYS66
VAL9
GLU24
|
P3
TYR
GLN114
ARG155
TYR159
LEU156
LYS66
GLU152
ASN70
|
P4
ARG
ARG155
ASN70
|
P5
TYR
TYR116
GLN114
ARG155
PHE74
SER99
SER73
VAL97
ASN70
VAL9
TYR7
|
P6
TYR
GLU152
TRP147
ASP77
ALA150
TYR116
ARG155
LYS146
|
P7
GLY
TRP147
ASP77
|
P8
LEU
LEU81
ILE95
TRP147
TYR123
ASP77
ILE124
THR80
TYR84
TYR116
ILE142
THR143
LYS146
|
Colour key
Data provenance
Neighbours are calculated by finding residues with atoms within 5Å of each other using BioPython Neighboursearch module. The list of neighbours is then sorted and filtered to inlcude only neighbours where between the peptide and the MHC Class I alpha chain.
Colours selected to match the YRB scheme. [https://www.frontiersin.org/articles/10.3389/fmolb.2015.00056/full]
A Pocket
TYR159
THR163
TRP167
TYR171
LEU5
TYR59
GLU63
LYS66
TYR7
|
B Pocket
GLU24
VAL34
TYR45
GLU63
LYS66
ALA67
TYR7
ASN70
VAL9
SER99
|
C Pocket
ASN70
SER73
PHE74
VAL9
VAL97
|
D Pocket
GLN114
ARG155
LEU156
TYR159
LEU160
SER99
|
E Pocket
GLN114
TRP147
GLU152
LEU156
VAL97
|
F Pocket
TYR116
TYR123
THR143
LYS146
TRP147
ASP77
THR80
LEU81
TYR84
ILE95
|
Colour key
Data provenance
1. Beta 2 microglobulin
Beta 2 microglobulin
|
10 20 30 40 50 60
IQKTPQIQVYSRHPPENGKPNILNCYVTQFHPPHIEIQMLKNGKKIPKVEMSDMSFSKDW 70 80 90 SFYILAHTEFTPTETDTYACRVKHDSMAEPKTVYWDRDM |
2. Class I alpha
H2-Kb
|
10 20 30 40 50 60
GPHSLRYFVTAVSRPGLGEPRYMEVGYVDDTEFVRFDSDAENPRYEPRARWMEQEGPEYW 70 80 90 100 110 120 ERETQKAKGNEQSFRVDLRTLLGYYNQSKGGSHTIQVISGCEVGSDGRLLRGYQQYAYDG 130 140 150 160 170 180 CDYIALNEDLKTWTAADMAALITKHKWEQAGEAERLRAYLEGTCVEWLRRYLKNGNATLL 190 200 210 220 230 240 RTDSPKAHVTHHSRPEDKVTLRCWALGFYPADITLTWQLNGEELIQDMELVETRPAGDGT 250 260 270 FQKWASVVVPLGKEQYYTCHVYHQGLPEPLTLRW |
3. Peptide
|
SIYRYYGL
|
4. T cell receptor alpha
T cell receptor alpha
TRAV9
|
10 20 30 40 50 60
QSVTQPDARVTVSEGASLQLRCKYSYSATPYLFWYVQYPRQGLQLLLKYYSGDPVVQGVN 70 80 90 100 110 120 GFEAEFSKSNSSFHLRKASVHWSDSAVYFCAVSGFASALTFGSGTKVIVLPYIQNPEPAV 130 140 150 160 170 180 YALKDPRSQDSTLCLFTDFDSQINVPKTMESGTFITDATVLDMKAMDSKSNGAIAWSNQT 190 200 SFTCQDIFKETNATYPSSDVPC |
5. T cell receptor beta
T cell receptor beta
TRBV13
|
10 20 30 40 50 60
EAAVTQSPRNKVAVTGGKVTLSCNQTNNHNNMYWYRQDTGHGLRLIHYSYGAGSTEKGDI 70 80 90 100 110 120 PDGYKASRPSQENFSLILELATPSQTSVYFCASGGGGTLYFGAGTRLSVLEDLRNVTPPK 130 140 150 160 170 180 VSLFEPSKAEIANKQKATLVCLARGFFPDHVELSWWVNGKEVHSGVSTDPQAYKESNYSY 190 200 210 220 230 CLSSRLRVSATFWHNPRNHFRCQVQFHGLSEEDKWPEGSPKPVTQNISAEAWGRADC |
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
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
This work is licensed under a Creative Commons Attribution 4.0 International License.