FIGURE 1.

Structure of the mCD3ϵ-Fab 2C11 complex. A, cartoon representation of the asymmetric unit containing one copy each of mCD3ϵ (red) and the Fab fragment from the CD3ϵ-specific monoclonal antibody 2C11 (gray). B, crystallographic homodimer of mCD3ϵ. The two CD3ϵ monomers are colored red and yellow, respectively. The top panel shows the contiguous β-sheet formed by anti-parallel pairing of the A-strands of the two monomers. The bottom panel shows a view after a 90° rotation about the horizontal axis. Boxes (i) and (ii) highlight the two main regions of interaction. C, ball-and-stick representation of the interaction between the A strands in box (i) from B. Potential hydrogen bonds are shown as dashed green lines. See also supplemental Figs. S1 and S2 and supplemental Table S1.