{"display":true,"structure":{"allele":{"alpha":{"identifier":"ipd-imgt:HLA35266","locus":"hla-a","match_type":"histo:fuzzy","name":"HLA-A*02:01","slug":"hla_a_02_01","species_stem":"hla"},"beta":{}},"assemblies":{"1":{"assembly_name":"4gup_1","chains":["A","B"],"downloaded_at":"2022-11-09T14:45:38.831484"},"2":{"assembly_name":"4gup_2","chains":["C","D"],"downloaded_at":"2022-11-09T14:45:40.662132"}},"assembly_count":null,"assigned_chains":{"beta2m":{"chains":["B","D"],"match_type":"histo:assign_chains","score":1.0,"sequence":"IQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM"},"mr1":{"chains":["A","C"],"match_type":"histo:assign_chains","score":1.0,"sequence":"MRTHSLRYFRLGVSDPIHGVPEFISVGYVDSHPITTYDSVTRQKEPRAPWMAENLAPDHWERYTQLLRGWQQMFKVELKRLQRHYNHSGSHTYQRMIGCELLEDGSTTGFLQYAYDGQDFLIFNKDTLSWLAVDNVAHTIKQAWEANQHELLYQKNWLEEECIAWLKRFLEYGKDTLQRTEPPLVRVNRKETFPGVTALFCKAHGFYPPEIYMTWMKNGEEIVQEIDYGDILPSGDGTYQAWASIELDPQSSNLYSCHVEHSGVHMVLQVP"}},"chronology":{"deposition_date":"2012-08-29","deposition_year":2012,"release_date":"2012-10-17","release_year":2012,"revision_date":"2012-12-05","revision_year":2012},"class":"class_i","classical":false,"complex_type":"mr1","components":["mr1","beta2m"],"experimental_method":"X-ray diffraction","facets":{},"ligands":[],"locus":"hla-a","manually_edited":{},"missing_residues":[],"page_title":"4GUP | Non-classical MHC Class I molecule MR1","pdb_code":"4gup","pdb_title":"Structure of MHC-Class I related molecule MR1","peptide":{"actual_sequence":null,"epitope_info":{},"features":[],"full_sequence":null,"gap_info":{},"gapped_sequence":null,"length":{"numeric":null,"text":null},"unnatural_amino_acids":[]},"publication":{"abstract":"Antigen-presenting molecules, encoded by the major histocompatibility complex (MHC) and CD1 family, bind peptide- and lipid-based antigens, respectively, for recognition by T cells. Mucosal-associated invariant T (MAIT) cells are an abundant population of innate-like T cells in humans that are activated by an antigen(s) bound to the MHC class I-like molecule MR1. Although the identity of MR1-restricted antigen(s) is unknown, it is present in numerous bacteria and yeast. Here we show that the structure and chemistry within the antigen-binding cleft of MR1 is distinct from the MHC and CD1 families. MR1 is ideally suited to bind ligands originating from vitamin metabolites. The structure of MR1 in complex with 6-formyl pterin, a folic acid (vitamin B9) metabolite, shows the pterin ring sequestered within MR1. Furthermore, we characterize related MR1-restricted vitamin derivatives, originating from the bacterial riboflavin (vitamin B2) biosynthetic pathway, which specifically and potently activate MAIT cells. Accordingly, we show that metabolites of vitamin B represent a class of antigen that are presented by MR1 for MAIT-cell immunosurveillance. As many vitamin biosynthetic pathways are unique to bacteria and yeast, our data suggest that MAIT cells use these metabolites to detect microbial infection.","bibjson":{"author":[{"initials":"L","lastname":"Kjer-Nielsen","name":"Kjer-Nielsen L"},{"initials":"O","lastname":"Patel","name":"Patel O"},{"initials":"AJ","lastname":"Corbett","name":"Corbett AJ"},{"initials":"J","lastname":"Le Nours","name":"Le Nours J"},{"initials":"B","lastname":"Meehan","name":"Meehan B"},{"initials":"L","lastname":"Liu","name":"Liu L"},{"initials":"M","lastname":"Bhati","name":"Bhati M"},{"initials":"Z","lastname":"Chen","name":"Chen Z"},{"initials":"L","lastname":"Kostenko","name":"Kostenko L"},{"initials":"R","lastname":"Reantragoon","name":"Reantragoon R"},{"initials":"NA","lastname":"Williamson","name":"Williamson NA"},{"initials":"AW","lastname":"Purcell","name":"Purcell AW"},{"initials":"NL","lastname":"Dudek","name":"Dudek NL"},{"initials":"MJ","lastname":"McConville","name":"McConville MJ"},{"initials":"RA","lastname":"O'Hair","name":"O'Hair RA"},{"initials":"GN","lastname":"Khairallah","name":"Khairallah GN"},{"initials":"DI","lastname":"Godfrey","name":"Godfrey DI"},{"initials":"DP","lastname":"Fairlie","name":"Fairlie DP"},{"initials":"J","lastname":"Rossjohn","name":"Rossjohn J"},{"initials":"J","lastname":"McCluskey","name":"McCluskey J"}],"identifier":[{"id":"10.1038/nature11605","type":"doi"},{"id":"23051753","type":"pubmed"}],"issue":[null],"journal":{"iso_abbreviation":"Nature","name":""},"pages":[null],"title":"MR1 presents microbial vitamin B metabolites to MAIT cells.","type":"article","url":"http://www.nature.com/articles/nature11605","volume":[null],"year":[2012]},"in_pmc":"N","in_pmce":"N","open_access":"N"},"resolution":"3.20","same_as":{"pdbe":{"url":"https://www.ebi.ac.uk/pdbe/entry/pdb/4gup"},"rcsb":{"url":"https://www.rcsb.org/structure/4gup"}},"species":{"common_name":"Human","match_type":"histo:assign_species","scientific_name":"Homo sapiens","slug":"homo_sapiens"},"tcr":null,"title":"Non-classical MHC Class I molecule MR1 at 3.20Å resolution","unique_chain_count":2}}