33CH: MAGE-A4 (230-239)-bound HLA-A*02:01

Cryo-EM structure of MAGE-A4 (230-239)-bound HLA-A*02:01 in complex with Fab VR-4. Determined by electron microscopy at 2.4 Å resolution. Released 26 Aug 2026.

Method
Electron microscopy
Resolution
2.4 Å
Organisms
Homo sapiens, Mus musculus
Chains
7
Atoms
6,682
Mol. weight
147.47 kDa
Released
26 Aug 2026

Explore 33CH in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

33CH contains 24 α-helices and 76 β-strands across 6 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: 10 helices, 20 β-strands

ElementResiduesLengthSheet
β-strand3-14121
β-strand18-28111
β-strand31-3771
β-strand46-4721
α-helix52-543
α-helix57-8428
β-strand94-103101
β-strand109-118101
β-strand121-12661
β-strand133-13531
α-helix138-14912
α-helix152-1587
α-helix159-1635
α-helix164-17411
α-helix176-1794
β-strand18312
α-helix184-1852
β-strand18613
β-strand189-19354
β-strand198-208114
β-strand20912
β-strand213-21975
β-strand222-22325
β-strand228-23034
α-helix231-2333
β-strand234-23524
β-strand241-250104
α-helix254-2563
β-strand257-26375
β-strand270-27345
Chain B: 3 helices, 11 β-strands
ElementResiduesLengthSheet
β-strand316
α-helix4-52
β-strand6-1167
β-strand21-30107
β-strand3116
β-strand36-4168
β-strand44-4528
α-helix461
β-strand50-5127
α-helix52-543
β-strand55-5627
β-strand62-7097
β-strand78-8368
β-strand91-9448
Chain D: 2 helices, 10 β-strands
ElementResiduesLengthSheet
β-strand4-7413
β-strand10-14514
β-strand19-291113
β-strand33-38614
β-strand45-49514
β-strand53-54214
α-helix551
β-strand62-751413
α-helix80-823
β-strand85-93914
β-strand96-100514
β-strand104-109614
Chain E: 2 helices, 12 β-strands
ElementResiduesLengthSheet
β-strand3-7515
β-strand11-12216
β-strand18-25815
β-strand34-40717
β-strand47-52617
β-strand58-60317
α-helix65-673
β-strand68-73615
β-strand78-83615
α-helix88-903
β-strand92-99817
β-strand105-108417
β-strand112-114317
β-strand115-116216
Chain F: 4 helices, 11 β-strands
ElementResiduesLengthSheet
β-strand4-749
β-strand10-13410
β-strand19-2579
β-strand33-38610
β-strand44-49610
β-strand53-54210
α-helix551
β-strand62-6769
β-strand70-7569
α-helix80-823
β-strand85-90610
α-helix971
β-strand98110
α-helix991
β-strand102-106510
Chain G: 3 helices, 12 β-strands
ElementResiduesLengthSheet
β-strand3-6411
β-strand10-12312
β-strand18-25811
α-helix29-313
β-strand34-39612
β-strand45-52812
β-strand57-60412
α-helix62-643
β-strand65111
β-strand68-73611
β-strand78-83611
α-helix88-903
β-strand92-100912
β-strand105-109512
β-strand113-117512

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
MHC class I antigenAprotein296Homo sapiensF6IQS1 (AlphaFold model)
Beta-2-microglobulinBprotein100Homo sapiensP61769 (AlphaFold model)
Melanoma-associated antigen 4Cprotein10Homo sapiensP43358 (AlphaFold model)
Fab BBM.1 light chainFprotein214Mus musculus
Fab BBM.1 heavy chainGprotein222Mus musculus
Fab VR-4 light chainDprotein216Homo sapiens
Fab VR-4 heavy chainEprotein273Homo sapiens
Sequence of entity 1 (A), FASTA
>33CH_1 MHC class I antigen (chains A)
MGSHSMRYFFTSVSRPGRGEPRFIAVGYVDDTQFVRFDSDAASQRMEPRAPWIEQEGPEY
WDGETRKVKAHSQTHRVDLGTLRGCYNQSEAGSHTVQRMYGCDVGSDWRFLRGYHQYAYD
GKDYIALKEDLRSWTAADMCAQTTKHKWEAAHVAEQLRAYLEGTCVEWLRRYLENGKETL
QRTDAPKTHMTHHAVSDHEATLRCWALSFYPAEITLTWQRDGEDQTQDTELVETRPAGDG
TFQKWAAVVVPSGQEQRYTCHVQHEGLPKPLTLRWEPGSGSGLNDIFEAQKIEWHE
Sequence of entity 2 (B), FASTA
>33CH_2 Beta-2-microglobulin (chains B)
MIQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKD
WSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM
Sequence of entity 3 (C), FASTA
>33CH_3 Melanoma-associated antigen 4 (chains C)
GVYDGREHTV
Sequence of entity 4 (F), FASTA
>33CH_4 Fab BBM.1 light chain (chains F)
DIQMTQSPASQSASLGESVTITCLASQTIGTWLAWYQQKPGKSPQLLIYAATSLADGVPS
RFSGSGSGTKFSLKIRTLQAEDFVSYYCQQLYSKPYTFGGGTKLEIKRTVAAPSVFIFPP
SDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLT
LSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC
Sequence of entity 5 (G), FASTA
>33CH_5 Fab BBM.1 heavy chain (chains G)
EVQLQQSGAELVKPGASVKLSCTPSGFNVKDTYIHWVKQRPKQGLEWIGRIDPSDGDIKY
DPKFQGKATITADTSSNTVSLQLSSLTSEDTAVYYCARWFGDYGAMNYWGQGTSVTVSSA
STKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG
LYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC
Sequence of entity 6 (D), FASTA
>33CH_6 Fab VR-4 light chain (chains D)
DIVMTQSPSSLSASVGDRVTITCQASQDINNYLNWYQQKPGKAPKLLIYDASNLETGVPS
RFSGSGSGTDFTFTISSLQPEDIATYFCQQYDNLPRSITFGQGTRLEIKRTVAAPSVFIF
PPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSST
LTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC
Sequence of entity 7 (E), FASTA
>33CH_7 Fab VR-4 heavy chain (chains E)
QVQLVQSGPGLVKPSGTLSLTCAVSGVSISSNKWWNWVRQPPGKGLEWIGEVYHSGSTNY
NPSLKSRVTISVDKSKNQFSLRLSSVTAADTAVYYCARDYSNYGFDYWGQGALVTVSSAS
TKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGL
YSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCAAAEQKLISEEDLNEMEQK
LISEEDLNEMEQKLISEEDLNEMAAHHHHHHHH

Primary citation

Systematic De-Risking of TCR-Mimic Therapeutics Through Proteome-Wide Off-Target Landscaping and a Generalizable Design Rule Framework. Schuster, S., Hartl, F.A., Stehle, J. et al. To be published.

Other PDB entries of the same protein (UniProt F6IQS1 (AlphaFold model), which also has an AlphaFold model), best resolution first:

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