22EE: HLA-A2:01 with 9-mer peptide PGS

Structure of HLA-A2:01 with 9-mer peptide PGS. Determined by X-ray diffraction at 1.99 Å resolution. Released 24 Jun 2026.

Method: X-ray diffraction
Resolution: 1.99 Å
Organisms: Homo sapiens, Toxoplasma gondii
Chains: 3
Atoms: 3,406
Mol. weight: 44.89 kDa
Released: 24 Jun 2026

Explore 22EE in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

22EE contains 14 α-helices and 30 β-strands across 2 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 12 helices, 19 β-strands

Element	Residues	Length	Sheet
β-strand	4-13	10	1
α-helix	21	1
β-strand	22-29	8	1
β-strand	32-38	7	1
β-strand	47-48	2	1
α-helix	51-53	3
α-helix	58-85	28
β-strand	95-104	10	1
β-strand	110-119	10	1
β-strand	122-127	6	1
β-strand	134-136	3	1
α-helix	139-150	12
α-helix	153-159	7
α-helix	160-164	5
α-helix	165-175	11
α-helix	177-180	4
β-strand	184	1	2
α-helix	185-186	2
β-strand	187-196	10	3
β-strand	199-209	11	3
β-strand	210	1	2
β-strand	215-220	6	4
β-strand	223-224	2	4
α-helix	226-228	3
β-strand	229-231	3	3
α-helix	232-234	3
β-strand	235-236	2	3
β-strand	242-251	10	3
α-helix	255-257	3
β-strand	258-263	6	4
β-strand	271-273	3	4

Chain B: 2 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	4	1	5
α-helix	5-6	2
β-strand	7-12	6	6
β-strand	22-31	10	6
β-strand	32	1	5
β-strand	37-42	6	7
β-strand	45-46	2	7
β-strand	51-52	2	6
α-helix	53-55	3
β-strand	56-57	2	6
β-strand	63-71	9	6
β-strand	79-84	6	7
β-strand	92-95	4	7

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
HLA class I antigen	A	protein	276	Homo sapiens	Q53Z42 (AlphaFold model)
Beta-2-microglobulin	B	protein	100	Homo sapiens	P61769 (AlphaFold model)
9-mer peptide from T. gondii glycogen synthase	C	protein	9	Toxoplasma gondii

Sequence of entity 1 (A), FASTA

>22EE_1 HLA class I antigen (chains A)
MGSHSMRYFFTSVSRPGRGEPRFIAVGYVDDTQFVRFDSDAASQRMEPRAPWIEQEGPEY
WDGETRKVKAHSQTHRVDLGTLRGYYNQSEAGSHTVQRMYGCDVGSDWRFLRGYHQYAYD
GKDYIALKEDLRSWTAADMAAQTTKHKWEAAHVAEQLRAYLEGTCVEWLRRYLENGKETL
QRTDAPKTHMTHHAVSDHEATLRCWALSFYPAEITLTWQRDGEDQTQDTELVETRPAGDG
TFQKWAAVVVPSGQEQRYTCHVQHEGLPKPLTLRWE

Sequence of entity 2 (B), FASTA

>22EE_2 Beta-2-microglobulin (chains B)
MIQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKD
WSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM

Sequence of entity 3 (C), FASTA

>22EE_3 9-mer peptide from T. gondii glycogen synthase (chains C)
SLWQLLQAA

Primary citation

Structure of HLA-A2:01 with the 9-mer peptide PGS. Li, Z.B., Liang, R.Y. To be published.

Other PDB entries of the same protein (UniProt Q53Z42 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6TRN 1.35 Å, Crystal structure of HLA A2*01-AVYDGREHTV
8FU4 1.6 Å, HCMV US11 peptide binding to HLA-A*02:01
7UM2 1.63 Å, SARS-CoV-2 Spike-derived peptide S417-425 K417T mutant (TIADYNYKL) presented by…
7U1R 1.8 Å, SARS-CoV-2 Spike-derived peptide S1185-1193 K1191N mutant (RLNEVANNL) presented by…
8RBV 1.8 Å, SARS-CoV-2 Spike-derived peptide S976-984 S982A mutant (VLNDILARL) presented by…
7RTD 2.05 Å, SARS-CoV-2 Spike-derived peptide S269-277 (YLQPRTFLL) presented by HLA-A*02:01
9MIN 2.05 Å, Structure of a designed minibinder to NYESO1-A*02:01
7UR1 2.17 Å, SARS-CoV-2 Spike-derived peptide S1215-1224 (YIWLGFIAGL) presented by HLA-A*02:01
7RTR 2.6 Å, YLQ-SG3 TCR in complex with SARS-CoV-2 Spike-derived peptide S269-277 (YLQPRTFLL)…
8TBV 2.64 Å, Human Class I MHC HLA-A2 in complex with sorting nexin 24 (127-135) neoantigen KLSHQLVLL
6TRO 3.0 Å, Crystal structure of the T-cell receptor GVY01 bound to HLA A2*01-GVYDGREHTV
9VSO 3.03 Å, Crystal structure of Fab bound to the WT1-derived RMF peptide presented by HLA-A*02:01

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