Fig. 6: TRAV26-1⁺ TCR recognition of HLA-DR4^{α-eno-15cit10-22V20G}.

a Left: Overall cartoon representation of human TCR RA2.7 complexed to HLA-DR4^{α-eno-15cit10-22V20G}. The HLA-DR4 α and β chains are coloured in white and brown, respectively. The peptide is coloured in orange sticks. The CDR loops 1α, 2α, and 3α are highlighted in cyan, violet, and light green colour, whereas 1β, 2β, 3β are coloured in blue, purple, and dark green, respectively. The FW α residues are colour in sand and β residues are colour in beige. Right Top: Surface representation of TCR footprints and TCR docking. TCR footprint colours are in accordance with the nearest TCR contact residue. The Vα and Vβ centre of mass position is shown in red and blue spheres, respectively, and connected via a black line. Right bottom: Pie charts present the relative contribution of each CDR loop and FW of TCR to the surface of HLA-DR4^{α-eno-15cit10-22V20G}. Detailed interactions of RA2.7 TCR between (b) CDR1α, 2α and 3α, (c) CDR1β, 2β, and FW β, d CDR3β with HLA-DR4 and (e) peptide interactions are shown. f Effect of RA2.7 TCR point mutations at the pMHC II interface. The SPR experiments were performed in duplicate (n = 2). The Y axis represents the fold of affinity of mutant TCRs as compared with wild-type TCR. The X axis represents the position of RA2.7 TCR mutants. The impact of each mutation was classified as negligible (<1.5-fold affinity decrease, blue), mild (1.5-fold to 3-fold affinity decrease, green), moderate (3-fold to 5-fold affinity reduction, orange), or critical (>5-fold affinity decrease or no binding, red). Source data are provided as a Source Data file.