6XQQ

Structure of human D462-E4 TCR

Summary for 6XQQ

• Entry DOI: 10.2210/pdb6xqq/pdb
• Descriptor: TRAV12-2 alpha chain, TRBV29-1, GLYCEROL, ... (4 entities in total)
• Functional Keywords: mait, mr1, metabolite presentation, immune system
• Biological source: Homo sapiens; More
• Total number of polymer chains: 4
• Total formula weight: 100961.99

Authors

Awad, W.,Rossjohn, J. (deposition date: 2020-07-10, release date: 2020-08-19, Last modification date: 2024-10-16)

Primary citation

Awad, W.,Meermeier, E.W.,Sandoval-Romero, M.L.,Le Nours, J.,Worley, A.H.,Null, M.D.,Liu, L.,McCluskey, J.,Fairlie, D.P.,Lewinsohn, D.M.,Rossjohn, J.
Atypical TRAV1-2 - T cell receptor recognition of the antigen-presenting molecule MR1.
J.Biol.Chem., 295:14445-14457, 2020

PubMed Abstract: MR1 presents vitamin B-related metabolites to mucosal associated invariant T (MAIT) cells, which are characterized, in part, by the TRAV1-2 αβ T cell receptor (TCR). In addition, a more diverse TRAV1-2 MR1-restricted T cell repertoire exists that can possess altered specificity for MR1 antigens. However, the molecular basis of how such TRAV1-2 TCRs interact with MR1-antigen complexes remains unclear. Here, we describe how a TRAV12-2 TCR (termed D462-E4) recognizes an MR1-antigen complex. We report the crystal structures of the unliganded D462-E4 TCR and its complex with MR1 presenting the riboflavin-based antigen 5-OP-RU. Here, the TRBV29-1 β-chain of the D462-E4 TCR binds over the F'-pocket of MR1, whereby the complementarity-determining region (CDR) 3β loop surrounded and projected into the F'-pocket. Nevertheless, the CDR3β loop anchored proximal to the MR1 A'-pocket and mediated direct contact with the 5-OP-RU antigen. The D462-E4 TCR footprint on MR1 contrasted that of the TRAV1-2 and TRAV36 TCRs' docking topologies on MR1. Accordingly, diverse MR1-restricted T cell repertoire reveals differential docking modalities on MR1, thus providing greater scope for differing antigen specificities.

PubMed: 32817339
DOI: 10.1074/jbc.RA120.015292

Experimental method

X-RAY DIFFRACTION (2.68 Å)