Continuum dynamics and statistical correction of compositional heterogeneity in multivalent IDP oligomers resolved by single-particle EM

摘要: Multivalent intrinsically disordered protein (IDP) complexes are prevalent in biology and control diverse cellular functions, including tuning levels of transcription, coordinating cell-signaling events, regulating the assembly disassembly complex macromolecular architectures. These systems pose a significant challenge to structural investigation, due continuum dynamics imparted by IDP compositional heterogeneity resulting from characteristic low-affinity interactions. Traditional single-particle electron microscopy (EM) is powerful tool for visualizing complexes. However, IDPs themselves typically "invisible" EM, undermining methods image analysis interpretation. To overcome these challenges, we developed pipeline automated common 9beads-on-a-string9 type assemblies, composed bound at multivalent sites ubiquitous ~20 kDa cross-linking hub LC8. This approach quantifies conformational on basis, statistically corrects spurious observations arising random proximity unbound After careful validation methodology, was applied nuclear pore Nup159 transcription factor ASCIZ. The unveiled diversity both that could not be obtained traditional single particle EM class-averaging strategies, shed new light how architectural properties contribute their physiological roles supramolecular transcriptional regulation. Ultimately, expect this may adopted many other have evaded characterization.