Fig. 1: p14^ARF exhibits local and long-range ordering within condensates with NPM1.

A NPM1 structural features, including the secondary structure calculated from the oligomerization domain (OD) PDB 4N8M and the nucleic acid binding domain (NBD) PDB 2LLH, using DSSP (2^o Struc.; β-strands are indicated with arrows and α-helicies are indicated with cylinders). The CIDER linear net charge per residue (LNCPR) and linear hydropathy (Hydro.) are shown for the IDR. B p14^ARF structural features, including PSI-PRED secondary structure prediction (2^o Struc.), CIDER linear net charge per residue (LNCPR), and linear hydropathy (Hydro.). The amino acid sequence conservation (Cons.) is based on a multiple sequence alignment using MUSCLE. The bottom panel shows the Rosetta steric zipper propensity energy (R. Energy) calculated using ZipperDB. C CV-SANS curves for p14^ARF-NPM1 condensates, in 100% D₂O buffer for full scattering intensity (NPM1 and p14^ARF detected; gray trace), in 45% D₂O buffer where p14^ARF is contrast matched ([²H]-NPM1 detected; green trace), and in 85% D₂O buffer where [²H]-NPM1 is contrast matched (p14^ARF detected; blue trace). Correlation peaks at ~200 Å and ~400 Å correspond to meso-scale organization of p14^ARF. All curves are offset for clarity. Scatter points represent the average, the error bars represent the uncertainty derived from the counting statistics of the SANS instrument, as described and cited in the Methods. D Schematic describing NPM1 with extended IDR conformations. E Schematic describing the spatial organization of p14^ARF within p14^ARF-NPM1 condensates. F 2D CC-DARR spectrum of [¹³C,¹⁵N]-p14^ARF within the condensed phase. Select resonance assignments are labeled. G Secondary ¹³C chemical shifts for [¹³C,¹⁵N]-p14^ARF within the condensed phase. Assigned residues are highlighted in gray. The secondary structure prediction from panel B is shown for reference (2^o Struc.; top).