9O60

Local refinement of 1C5H TCR bound to R-phycoerythrin (gamma chain dimer)

Summary for 9O60

• Entry DOI: 10.2210/pdb9o60/pdb
• EMDB information: 70155
• Descriptor: 1C5H TCR gamma chain, 1C5H TCR delta chain (2 entities in total)
• Functional Keywords: t-cell, gamma delta tcr, phycoerythrin, direct, immune system
• Biological source: Homo sapiens; More
• Total number of polymer chains: 3
• Total formula weight: 80915.64

Authors

Rashleigh, L.,Venugopal, H.,Rossjohn, J.,Gully, B.S. (deposition date: 2025-04-10, 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 (2.63 Å)