Visualizing the Molecular Recognition Trajectory of an Intrinsically Disordered Protein Using Multinuclear Relaxation Dispersion NMR

• Published in: Journal of the American Chemical Society 2015-01, Vol.137 (3), p.1220-1229
• Main Authors: Schneider, Robert, Maurin, Damien, Communie, Guillaume, Kragelj, Jaka, Hansen, D. Flemming, Ruigrok, Rob W. H, Jensen, Malene Ringkjøbing, Blackledge, Martin
• Format: Article
• Language: English
• Subjects: Biochemistry, Molecular Biology; Life Sciences; Models, Molecular; Nuclear Magnetic Resonance, Biomolecular; Nucleoproteins - chemistry; Phosphoproteins - chemistry; Sendai virus - chemistry; Structural Biology
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja511066q

Despite playing important roles throughout biology, molecular recognition mechanisms in intrinsically disordered proteins remain poorly understood. We present a combination of 1HN, 13C′, and 15N relaxation dispersion NMR, measured at multiple titration points, to map the interaction between the disordered domain of Sendai virus nucleoprotein (NT) and the C-terminal domain of the phosphoprotein (PX). Interaction with PX funnels the free-state equilibrium of NT by stabilizing one of the previously identified helical substates present in the prerecognition ensemble in a nonspecific and dynamic encounter complex on the surface of PX. This helix then locates into the binding site at a rate coincident with intrinsic breathing motions of the helical groove on the surface of PX. The binding kinetics of complex formation are thus regulated by the intrinsic free-state conformational dynamics of both proteins. This approach, providing high-resolution structural and kinetic information about a complex folding and binding interaction trajectory, can be applied to a number of experimental systems to provide a general framework for understanding conformational disorder in biomolecular function.