Fig. 4.
Molecular surface of CD3-ε/δ and UCHT1 contact residues. Positive and negative electrostatic surface potentials of CD3-ε/δ dimer are indicated on the translucent molecular surface in blue and red, respectively. CD3-ε/δ is oriented as in Fig. 1. CD3-ε and UCHT1 contact residues, which form hydrogen bonds or salt bridges, are indicated as ball-and-stick models. UCHT1 light chain (yellow) and heavy chain (green) bind exclusively to CD3-ε near an electronegative region on the side (indicated with an arrow), partially occluding it and burying a molecular surface of 1,789 Å2.