Figure S4.

Crystal structure images. (A) Electron density of ligand pockets in the E8 TCR-MR1 crystal structures. MR1 (gray) K43 residue and the covalently bound ligands are shown in sticks. (B) Calculated per-residue contributions to the binding free energy for both the E8 and AF-7 TCRs in complex with MR1 5-OP-RU and the empty MR1 K43A (and therefore in the absence of 5-OP-RU). The MR1 and TCR molecules are shown as surface and color mapped according to their MMPBSA calculated per-residue decomposition energies. Color mapping goes from blue (favorable binding) to white (neutral) to red (unfavorable binding) as indicated by the color bar. Equivalent plots for both TCR–MR1 complexes with 5-OP-RU bound.