Fig. 5.

Disordered N-terminal RGG domain drives phase separation and RNA/protein dynamics. (A) The PONDR algorithm predicts a high degree of disorder for both N and C termini of LAF-1. (B) Circular dichroism spectra indicate that the N-terminal RGG domain resembles a random coil, whereas FL, ΔC, and ΔRGG constructs contain secondary structure dominated by alpha helical conformation. (C) Schematic of LAF-1 deletion constructs. (Right) Droplets formed in 125 mM NaCl with DyLight-488–labeled protein for the indicated LAF-1 construct. (D) Single molecule FRET traces were recorded for 2 μM protein and 125 mM NaCl. The RGG domain is necessary and sufficient for dynamic RNA–protein interactions.