Fig. 3.
Kapβ1-FG binding activity and cNup62 form–function are intimately coupled. (1) A local collapse of cNup62 occurs around Kapβ1 owing to strong multivalent Kapβ1-FG (dark green) binding at low ρKapβ1. (2) Additional Kapβ1 molecules bind tightly in the cNup62 layer, driving unoccupied FG domains to extend or recover because of increasing in-layer steric repulsion whereupon the layer self-heals, reaching Δd = 0. (3) At high ρKapβ1, a secondary layer of Kapβ1 (light green) binds weakly to unoccupied FG domain protrusions giving Δd > 0. Red dashed lines correspond to the cNup62 layer height as measured by BSA (red watermarked).