{"display":true,"structure":{"allele":{"alpha":{"identifier":"ipd-imgt:HLA35266","locus":"hla-a","match_type":"histo:exact","name":"HLA-A*02:01","slug":"hla_a_02_01","species_stem":"hla"},"beta":{}},"assemblies":{"1":{"assembly_name":"3hla_1","chains":["A","B"],"downloaded_at":"2022-11-09T14:31:54.095605"}},"assembly_count":null,"assigned_chains":{"beta2m":{"chains":["B"],"match_type":"histo:assign_chains","score":1.0,"sequence":"IQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM"},"class_i_alpha":{"chains":["A"],"match_type":"histo:assign_chains","score":0.99,"sequence":"GSHSMRYFFTSVSRPGRGEPRFIAVGYVDDTQFVRFDSDAASQRMEPRAPWIEQEGPEYWDGETRKVKAHSQTHRVDLGTLRGYYNQSEAGSHTVQRMYGCDVGSDWRFLRGYHQYAYDGKDYIALKEDLRSWTAADMAAQTTKHKWEAAHVAEQLRAYLEGTCVEWLRRYLENGKETLQRTDAPKTHMTHHAVSDHEATLRCWALSFYPAEITLTWQRDGEDQTQDTELVETRPAGDGTFQKWAAVVVPSGQEQRYTCHVQHEGLPKPL"}},"chronology":{"deposition_date":"1989-10-06","deposition_year":1989,"release_date":"1990-04-15","release_year":1990,"revision_date":"2011-07-13","revision_year":2011},"class":"class_i","classical":true,"complex_type":"class_i_possibly_without_peptide","components":["class_i_alpha","beta2m"],"experimental_method":"X-ray diffraction","facets":{},"ligands":[],"locus":"hla-a","manually_edited":{},"missing_residues":[],"page_title":"3HLA | HLA-A*02:01 possibly without \"peptide\"","pdb_code":"3hla","pdb_title":"Human Class I histocompatibility antigen a2.1","peptide":{"actual_sequence":null,"epitope_info":{},"features":[],"full_sequence":null,"gap_info":{},"gapped_sequence":null,"length":{"numeric":null,"text":null},"unnatural_amino_acids":[]},"pockets":{"a":{"a159":{"number":159,"one_letter":"Y","three_letter":"TYR"},"a163":{"number":163,"one_letter":"T","three_letter":"THR"},"a167":{"number":167,"one_letter":"W","three_letter":"TRP"},"a171":{"number":171,"one_letter":"Y","three_letter":"TYR"},"a5":{"number":5,"one_letter":"M","three_letter":"MET"},"a59":{"number":59,"one_letter":"Y","three_letter":"TYR"},"a63":{"number":63,"one_letter":"E","three_letter":"GLU"},"a66":{"number":66,"one_letter":"K","three_letter":"LYS"},"a7":{"number":7,"one_letter":"Y","three_letter":"TYR"}},"b":{"a24":{"number":24,"one_letter":"A","three_letter":"ALA"},"a34":{"number":34,"one_letter":"V","three_letter":"VAL"},"a45":{"number":45,"one_letter":"M","three_letter":"MET"},"a63":{"number":63,"one_letter":"E","three_letter":"GLU"},"a66":{"number":66,"one_letter":"K","three_letter":"LYS"},"a67":{"number":67,"one_letter":"V","three_letter":"VAL"},"a7":{"number":7,"one_letter":"Y","three_letter":"TYR"},"a70":{"number":70,"one_letter":"H","three_letter":"HIS"},"a9":{"number":9,"one_letter":"F","three_letter":"PHE"},"a99":{"number":99,"one_letter":"Y","three_letter":"TYR"}},"c":{"a70":{"number":70,"one_letter":"H","three_letter":"HIS"},"a73":{"number":73,"one_letter":"T","three_letter":"THR"},"a74":{"number":74,"one_letter":"H","three_letter":"HIS"},"a9":{"number":9,"one_letter":"F","three_letter":"PHE"},"a97":{"number":97,"one_letter":"R","three_letter":"ARG"}},"d":{"a114":{"number":114,"one_letter":"H","three_letter":"HIS"},"a155":{"number":155,"one_letter":"Q","three_letter":"GLN"},"a156":{"number":156,"one_letter":"L","three_letter":"LEU"},"a159":{"number":159,"one_letter":"Y","three_letter":"TYR"},"a160":{"number":160,"one_letter":"L","three_letter":"LEU"},"a99":{"number":99,"one_letter":"Y","three_letter":"TYR"}},"e":{"a114":{"number":114,"one_letter":"H","three_letter":"HIS"},"a147":{"number":147,"one_letter":"W","three_letter":"TRP"},"a152":{"number":152,"one_letter":"V","three_letter":"VAL"},"a156":{"number":156,"one_letter":"L","three_letter":"LEU"},"a97":{"number":97,"one_letter":"R","three_letter":"ARG"}},"f":{"a116":{"number":116,"one_letter":"Y","three_letter":"TYR"},"a123":{"number":123,"one_letter":"Y","three_letter":"TYR"},"a143":{"number":143,"one_letter":"T","three_letter":"THR"},"a146":{"number":146,"one_letter":"K","three_letter":"LYS"},"a147":{"number":147,"one_letter":"W","three_letter":"TRP"},"a77":{"number":77,"one_letter":"D","three_letter":"ASP"},"a80":{"number":80,"one_letter":"T","three_letter":"THR"},"a81":{"number":81,"one_letter":"L","three_letter":"LEU"},"a84":{"number":84,"one_letter":"Y","three_letter":"TYR"},"a95":{"number":95,"one_letter":"V","three_letter":"VAL"}}},"publication":{"abstract":"The three-dimensional structure of the human histocompatibility antigen HLA-A2 was determined at 3.5 A resolution by a combination of isomorphous replacement and iterative real-space averaging of two crystal forms. The monoclinic crystal form has now been refined by least-squares methods to an R-factor of 0.169 for data from 6 to 2.6 A resolution. A superposition of the structurally similar domains found in the heterodimer, alpha 1 onto alpha 2 and alpha 3 onto beta 2m, as well as the latter pair onto the ancestrally related immunoglobulin constant domain, reveals that differences are mainly in the turn regions. Structural features of the alpha 1 and alpha 2 domains, such as conserved salt-bridges that contribute to stability, specific loops that form contacts with other domains, and the antigen-binding groove formed from two adjacent helical regions on top of an eight-stranded beta-sheet, are analyzed. The interfaces between the domains, especially those between beta 2m and the HLA heavy chain presumably involved in beta 2m exchange and heterodimer assembly, are described in detail. A detailed examination of the binding groove confirms that the solvent-accessible amino acid side-chains that are most polymorphic in mouse and human alleles fill up the central and widest portion of the binding groove, while conserved side-chains are clustered at the narrower ends of the groove. Six pockets or sub-sites in the antigen-binding groove, of diverse shape and composition, appear suited for binding side-chains from antigenic peptides. Three pockets contain predominantly non-polar atoms; but others, especially those at the extreme ends of the groove, have clusters of polar atoms in close proximity to the \"extra\" electron density in the binding site. A possible role for beta 2m in stabilizing permissible peptide complexes during folding and assembly is presented.","bibjson":{"author":[{"initials":"MA","lastname":"Saper","name":"Saper MA"},{"initials":"PJ","lastname":"Bjorkman","name":"Bjorkman PJ"},{"initials":"DC","lastname":"Wiley","name":"Wiley DC"}],"identifier":[{"id":"10.1016/0022-2836(91)90567-p","type":"doi"},{"id":"2038058","type":"pubmed"}],"issue":["2"],"journal":{"iso_abbreviation":"J. Mol. Biol.","name":""},"pages":["277-319"],"title":"Refined structure of the human histocompatibility antigen HLA-A2 at 2.6 A resolution.","type":"article","url":"https://www.sciencedirect.com/science/article/abs/pii/002228369190567P","volume":["219"],"year":[1991]},"in_pmc":"N","in_pmce":"N","open_access":"N"},"resolution":"2.60","same_as":{"pdbe":{"url":"https://www.ebi.ac.uk/pdbe/entry/pdb/3hla"},"rcsb":{"url":"https://www.rcsb.org/structure/3hla"}},"species":{"common_name":"Human","match_type":"histo:assign_species","scientific_name":"Homo sapiens","slug":"homo_sapiens"},"tcr":null,"title":"HLA-A*02:01 possibly without \"peptide\" at 2.60Å resolution","unique_chain_count":2}}