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6P2C

HLA-B*08:01 binding "RARARARARARAAAKKKYCL" at 1.40Å resolution

Data provenance

Structure downloaded from PDB Europe using the Coordinate Server. Aligned to residues 1-180 of 1HHK2 using the CEALIGN3 function of PyMol4. Chain assigment using a Levenshtein distance5 method using data from the PDBe REST API6. Organism data from PDBe REST API. Data for both of these operations from the Molecules endpoint. Structure visualised with 3DMol7.

Information sections


Complex type

Class i with peptide

1. Beta 2 microglobulin
['B']
2. Class I alpha
HLA-B*08:01
['A']
['C']

Species


Locus / Allele group


Publication

ERAP1 enzyme-mediated trimming and structural analyses of MHC I--bound precursor peptides yield novel insights into antigen processing and presentation.

Li L, Batliwala M, Bouvier M
J. Biol. Chem. (2019) [doi:10.1074/jbc.ra119.010102]  [pubmed:31601650

Endoplasmic reticulum aminopeptidase 1 (ERAP1) and ERAP2 critically shape the major histocompatibility complex I (MHC I) immunopeptidome. The ERAPs remove N-terminal residues from antigenic precursor peptides and generate optimal-length peptides (i.e. 8-10-mers) to fit into the MHC class I groove. It is therefore intriguing that MHC class I molecules can present N-terminally extended peptides on the cell surface that can elicit CD8+ T-cell responses. This observation likely reflects gaps in our understanding of how antigens are processed by the ERAP enzymes. To better understand ERAPs' function in antigen processing, here we generated a nested set of N-terminally extended 10-20-mer peptides (RA) n AAKKKYCL covalently bound to the human leukocyte antigen (HLA)-B*0801. We used X-ray crystallography, thermostability assessments, and an ERAP1-trimming assay to characterize these complexes. The X-ray structures determined at 1.40-1.65 Å resolutions revealed that the residue extensions (RA) n unexpectedly protrude out of the A pocket of HLA-B*0801, whereas the AAKKKYCL core of all peptides adopts similar, bound conformations. HLA-B*0801 residue 62 was critical to open the A pocket. We also show that HLA-B*0801 and antigenic precursor peptides form stable complexes. Finally, ERAP1-mediated trimming of the MHC I-bound peptides required a minimal length of 14 amino acids. We propose a mechanistic model explaining how ERAP1-mediated trimming of MHC I-bound peptides in cells can generate peptides of canonical as well as noncanonical lengths that still serve as stable MHC I ligands. Our results provide a framework to better understand how the ERAP enzymes influence the MHC I immunopeptidome.

Structure deposition and release

Deposited: 2019-05-21
Released: 2019-10-16
Revised: 2019-12-18

Data provenance

Publication data retrieved from PDBe REST API8 and PMCe REST API9

Other structures from this publication


Peptide details

Length: Eicosamer (20 amino acids)

Sequence: RARARARARARAAAKKKYCL

Interactive view
Cutaway side view (static)
Surface top view (static - coloured by atom property)
Cutaway top view (static)

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 ALA

THR163
ASN63
TRP167
TYR159
ARG62
ILE66
P2 ALA

TRP167
TYR59
TYR7
THR163
ASN63
TYR171
TYR159
P3 ALA

ASN63
TYR159
PHE67
ILE66
TYR7
GLU45
P4 LYS

TYR159
TYR7
ILE66
TYR116
ASN70
TYR99
ASN114
ASP156
P5 LYS

ILE66
ASN70
ASP156
P6 LYS

TYR116
ASN70
TYR99
PHE22
THR73
ASP9
ASP74
SER97
P7 TYR

VAL152
TRP147
SER77
ASP156
GLN155
THR73
P8 CYS

ASN80
TRP147
CYS76
THR73
SER77
P9 LEU

THR143
TYR84
TYR116
LEU81
SER77
ASN80
TRP147
LEU95
TYR123
ILE124
LYS146

Colour key

Aromatic Hydrophobic Acidic Basic Neutral/polar

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]


Binding cleft pockets


Peptide sidechain binding pockets (static)
Peptide terminii and backbone binding residues (static)
A Pocket

TYR159
THR163
TRP167
TYR171
MET5
TYR59
ASN63
ILE66
TYR7
B Pocket

SER24
VAL34
GLU45
ASN63
ILE66
PHE67
TYR7
ASN70
ASP9
TYR99
C Pocket

ASN70
THR73
ASP74
ASP9
SER97
D Pocket

ASN114
GLN155
ASP156
TYR159
LEU160
TYR99
E Pocket

ASN114
TRP147
VAL152
ASP156
SER97
F Pocket

TYR116
TYR123
THR143
LYS146
TRP147
SER77
ASN80
LEU81
TYR84
LEU95

Colour key

Binds N-terminus Binds P1 backbone Binds P2 backbone Binds PC-1 backbone Binds C-terminus

Data provenance

N-/C-terminus and peptide backbone binding residues are assigned according to previously published information and pockets are assigned according to an adaptation of a previously published set of residues. All numbering is currently that of the 'canonical' structures of human and mouse MHC Class I molecules.

Chain sequences

1. Beta 2 microglobulin
Beta 2 microglobulin
        10        20        30        40        50        60
IQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDW
        70        80        90
SFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM

2. Class I alpha
HLA-B*08:01
IPD-IMGT/HLA
[ipd-imgt:HLA34671]
        10        20        30        40        50        60
GSHSMRYFDTAMSRPGRGEPRFISVGYVDDTQFVRFDSDAASPREEPRAPWIEQEGPEYW
        70        80        90       100       110       120
DRNTQIFKTNTQTDRCSLRNLRGYYNQSEAGSHTLQSMYGCDVGPDGRLLRGHNQYAYDG
       130       140       150       160       170       180
KDYIALNEDLRSWTAADTAAQITQRKWEAARVAEQDRAYLEGTCVEWLRRYLENGKDTLE
       190       200       210       220       230       240
RADPPKTHVTHHPISDHEATLRCWALGFYPAEITLTWQRDGEDQTQDTELVETRPAGDRT
       250       260       270
FQKWAAVVVPSGEEQRYTCHVQHEGLPKPLTLRWEP

3. Peptide
RARARARARARAAAKKKYCL


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

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Complete structures

Aligned structures [cif]
  1. 6P2C assembly 1  

Components

MHC Class I alpha chain [cif]
  1. 6P2C assembly 1  
MHC Class I antigen binding domain (alpha1/alpha2) [cif]
  1. 6P2C assembly 1  
Peptide only [cif]
  1. 6P2C assembly 1  

Derived data

Data for this page [json]
https://api.histo.fyi/v1/structures/6p2c

Data license

The data above is made available under a Creative Commons CC-BY 4.0 license. This means you can copy, remix, transform, build upon and redistribute the material, but you must give appropriate credit, provide a link to the license, and indicate if changes were made.
If you use any data downloaded from this site in a publication, please cite 'https://www.histo.fyi/'. A preprint is in preparation.

Footnotes