CryoEM structure of anti-MHC-I mAb B1.23.2 complex with HLA-B44:05

2026-03-18 REL RCSB INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY DATABASE_REFERENCES citation citation_author em_admin _citation.country _citation.journal_abbrev _citation.journal_id_CSD _citation.journal_id_ISSN _citation.pdbx_database_id_DOI _citation.pdbx_database_id_PubMed _citation.title _citation.year _em_admin.last_update EXPERIMENTAL_SUMMARY citation citation_author em_admin _citation.country _citation.journal_abbrev _citation.journal_id_CSD _citation.journal_id_ISSN _citation.pdbx_database_id_DOI _citation.pdbx_database_id_PubMed _citation.title _citation.year _em_admin.last_update DATABASE_REFERENCES citation citation_author em_admin _citation.journal_volume _citation_author.identifier_ORCID _em_admin.last_update EXPERIMENTAL_SUMMARY citation citation_author em_admin _citation.journal_volume _citation_author.identifier_ORCID _em_admin.last_update RCSB RCSB 2024-08-16 2026-02-04 2026-02-04 2026-03-18 National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID) Intramural United States CryoEM structure of anti-MHC-I mAb B1.23.2 complex with HLA-B44:05 Jiang J Natarajan K Lei H Huang R Margulies DH MHC-I, anti-human-mAb, H2-Dd, B1.23.2, anti-MHC-I antibody, anti-tumor, cancer immunotherapy, ANTITUMOR PROTEIN, ANTITUMOR PROTEIN-Immune System complex Jiang J Panda AK Natarajan K Lei H Sharma S Boyd LF Towler RR Chempati S Ahmad J Morton AJ Lang ZC Sun Y Sgourakis N Meier-Schellersheim M Huang RK Shevach EM Margulies DH Structural mechanism of anti-MHC-I antibody blocking of inhibitory NK cell receptors in tumor immunity. Commun Biol UK 9 2026 41629525 doi:10.1038/s42003-026-09641-8 2399-3642 9d73 FULLOVERLAP PDB 8TQ6 unspecified EMDB EMD-46601 associated EM volume

Complex of Anti-human-mAb B1.23.2 and MHC-I HLA-B44:05 Complex of Anti-human-mAb B1.23.2 and MHC-I HLA-B44:05 0 1 2 3 4 5

The sample was mixed 1:1 mole ratio of antibody and HLA-B44 and purified. with concentration of 1.0 mg/ml

Homo sapiens 0.196472 HLA class I histocompatibility antigen B alpha chain (HLA-B*44:05) Homo sapiens 0.031802119 1 Escherichia coli BL21(DE3) LEVO GSHSMRYFYTAMSRPGRGEPRFITVGYVDDTLFVRFDSDATSPRKEPRAPWIEQEGPEYWDRETQISKTNTQTYRENLRT ALRYYNQSEAGSHIIQRMYGCDVGPDGRLLRGYDQYAYDGKDYIALNEDLSSWTAADTAAQITQRKWEAARVAEQDRAYL EGLCVESLRRYLENGKETLQRADPPKTHVTHHPISDHEVTLRCWALGFYPAEITLTWQRDGEDQTQDTELVETRPAGDRT FQKWAAVVVPSGEEQRYTCHVQHEGLPKPLTLRW Q860B7 Beta-2-microglobulin Homo sapiens 0.011879355999999999 1 Escherichia coli BL21(DE3) LEVO MIQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYLLYYTEFTPTEKDEYA CRVNHVTLSQPKIVKWDRDM P61769 MHC class II antigen peptide synthetic construct 0.001090165 1 LEVO EEFGRAFSF Q9TQB0 B1.23.2 mAb Heavy Chain: Full-length Homo sapiens 0.048506444999999995

B1.23.2 mAb VH, CH1 of human IgG1, and CH2, CH3 domains, including the hinge (213-226) and LALAPG mutations (A230, A231, and G325)

1 Homo sapiens LEVO QVQLQQSGTVLARPGSSVKMSCKASGYSFTSYWMHWVKQRPGQGLEWIGAIYPGNSDATYNQKFKGKAKLTAVTSANTAY MELSSLTNEDSAVYYCTNYFDQWGQGTTLTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALT SGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFP PKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKALGAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSF FLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK B1.23.2 Light Chain: VL and C kappa domains Homo sapiens 0.023846432 1 Homo sapiens LEVO DIQMTQTPSSMYASLGERVTITCKASQDINSYLNWFQLKPGKSPKTLIYRANRLVDGVPSRFSGSGSGQDYSLTISSLEY EDMGIYYCLQYDELYTFGGGTKLEMKRADAAPTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLN SWTDQDSKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRNEC singleParticle particle 1.0 8.0 0.25 TBS EMS Lacey Carbon GOLD 300 CARBON HOLEY 1200.0 GLOW DISCHARGE 60 AIR ETHANE 95 277 FEI VITROBOT MARK IV TFS KRIOS FLOOD BEAM BRIGHT FIELD FIELD EMISSION GUN 300 100.0 2.7 0.7000000000000001 2.0 105000.0 60096.0 FEI TITAN KRIOS AUTOGRID HOLDER NITROGEN 78.0 80.0 GATAN K3 (6k x 4k) SUPER-RESOLUTION 1 7154 2.5 54.2 1 664724 cryoSPARC 4.4.1

PATCH CTF estimation

NONE 8TQ6 48 C1 SIMULTANEOUS ITERATIVE (SIRT) 3.02 FSC 0.143 CUT-OFF cryoSPARC 4.4.1 359876 NOT APPLICABLE NOT APPLICABLE 41 cryoSPARC 4.4.1 emd_46601.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 288 288 288 0 0 0 288 288 288 239.04 239.04 239.04 90.0 90.0 90.0 X Y Z -0.2950346 0.5683547 0.0006791331 0.011723799 0.83 0.83 0.83 0.1 AUTHOR ::::EMDATABANK.org::::EMD-46601:::: mai map file 8TQ6 PDB experimental model RIGID BODY FIT CC REAL 128.800000000000011 emd_46601_msk_1.map emd_46601_half_map_2.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 288 288 288 0 0 0 288 288 288 239.04 239.04 239.04 90.0 90.0 90.0 X Y Z -0.40388894 0.64678794 0.00044759127 0.035440117 0.83 0.83 0.83 AUTHOR ::::EMDATABANK.org::::EMD-46601:::: half map B emd_46601_half_map_1.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 288 288 288 0 0 0 288 288 288 239.04 239.04 239.04 90.0 90.0 90.0 X Y Z -0.3622709 0.61789775 0.00044720178 0.035379194 0.83 0.83 0.83 AUTHOR ::::EMDATABANK.org::::EMD-46601:::: half map A