Fig. 3: Scaling law of the NUP98 FG domain.
From: Visualizing the disordered nuclear transport machinery in situ
On the left, the NUP98 FG domain showed more extended conformations inside the functional NPC (scaling exponent ν = 0.56 ± 0.03) and in the phase-separated condensate (NUP98 FG droplets on coverslips) (ν = 0.56 ± 0.04). The NUP98 FG domain at picomolar concentration showed a more collapsed conformation in physiological buffer on a single-molecule level (ν = 0.29 ± 0.01). Three reference lines at the theta-solvent state (ν = 0.5; dashed grey lines) are plotted, because the prefactor of the scaling law is unknown for a heteropolymer under different solvent conditions. The NUP98 FG domain in the NPC was labelled with AZDye594 tetrazine and LD655 tetrazine. The purified NUP98 FG domain in the phase-separated condensate and in the solution was labelled with Alexa Fluor 594 maleimide and LD655 maleimide. On the right, schematics show the conformations of FG-NUPs inside the NPC associated with extreme scaling exponents. If ν ~ 1, FG domains behave like densely grafted polymer brushes. If ν ~ 0.3, FG domains adopt a collapsed conformation.
