FIGURE 6.

Model of VCAM binding to a natalizumab Fab-α₄β₁ complex. Transparent solvent accessible surfaces are shown of the α₄ β-propeller domain (wheat), β₁ βI domain (light blue), and natalizumab Fab (gray). Two examples of VCAM D1D2 crystal structures (chain A from Ref. 28 and chain B from Ref. 29) that differ the most in D1-D2 orientation are shown in ribbon representation, docked as described (11). The model of α₄β₁ is described in the legend to Fig. 5. Strong clashes show regions where the schematic is largely obscured by the transparent surface.