9MKO

4D4 TCR bound to R-phycoerythrin

Summary for 9MKO

• Entry DOI: 10.2210/pdb9mko/pdb
• EMDB information: 48332
• Descriptor: R-phycoerythrin class I alpha subunit, R-phycoerythrin class I beta subunit, 4D4 TCR alpha chain, ... (6 entities in total)
• Functional Keywords: tcr, phycoerythrin, immunity, direct recognition, immune system
• Biological source: Mus musculus; More
• Total number of polymer chains: 14
• Total formula weight: 283402.45

Authors

Rashleigh, L.,Gully, B.S.,Rossjohn, J. (deposition date: 2024-12-17, release date: 2025-08-06, Last modification date: 2025-10-15)

Primary citation

Rashleigh, L.,Venugopal, H.,Rice, M.T.,Gunasinghe, S.D.,Sok, C.L.,Gherardin, N.A.,Almeida, C.F.,Van Rhijn, I.,Moody, D.B.,Godfrey, D.I.,Rossjohn, J.,Gully, B.S.
Antibody-like recognition of a gamma delta T cell receptor toward a foreign antigen.
Structure, 33:1649-, 2025

PubMed Abstract: The antigen recognition principles of B cells and αβ T cells have been well described compared to those of the γδ T cell. By way of their specificity conferring receptor (γδTCR), γδ T cells can directly bind proteinaceous antigens. A known γδ T cell and B cell model antigen is phycoerythrin (PE), a light harvesting protein from rhodophytes and cyanobacteria. Here we probed human γδTCR reactivity to PE, in which a Vδ1Vγ5 TCR bound directly to induce proximal signaling and cellular activation. We determined the cryoelectron microscopy (cryo-EM) structure of the γδTCR-phycoerythrin immune complex. We then determined the cryo-EM structures of an antibody fragment and an αβTCR bound to PE. This revealed convergent use of apical aromatic residues to mediate contacts with a common PE epitope. Comparative analyses of the γδTCR revealed multiple antibody-like characteristics, including an enrichment of apical aromatic residues. Our findings reveal further distinct facets of antigen recognition by the γδTCR.

PubMed: 40744007
DOI: 10.1016/j.str.2025.07.006

Experimental method

ELECTRON MICROSCOPY (3.21 Å)