Extended Data Fig. 9: Domain architectures and multiple sequence alignments of NONO proteins.
From: Oxidative cyclization reagents reveal tryptophan cation–π interactions
a) Crystal structure of NONO (PDB: 3sde) with one native tryptophan residue on the surface shown in stick form. b) NONO W271 located in the NOPS domain. c) NONO W271 and pairing R220 are highly conserved across diverse species, while the neighbouring R293 is not. d) The role of FBRL-W137. Mutation of W137 on the intrinsically disordered region to alanine inhibited FBRL phase separation and normal nucleolus formation. Scale bar: 5 µm. n = 3 biological independent replicates; mean ± SE. e) The role of DDX3X-W60. Mutation of W60 on the intrinsically disordered region to alanine inhibited DDX3X phase separation and stress granule formation. Scale bar: 5 µm. n = 3 biological independent replicates; mean ± SE. f) The highly surface-exposed NONO W271 could form interprotein cation-π interactions with PSPC1 R228, SFPQ R443, and R220 on another NONO protein molecule. NONO-PSPC1: PDB (3SDE); NONO-SFPQ: PDB (7LRQ). g) Model of tryptophan cation-π interactions (intraprotein or interprotein) regulating phase separation behaviour of protein targets. Image created with BioRender.com.
