Direct Characterization of Inter-Domain Concerted Motions in Proteins from NMR

Abstract

The high resolution description of concerted inter-domain motions in proteins is a major challenge in molecular biophysics. Here we show that residual dipolar couplings (RDCs) measured by nuclear magnetic resonance (NMR) in solution under steric alignment provide information on the degree of concert of the inter-domain motions of two relatively simple representative multi-domain proteins: bacteriophage T4 Lysozyme (T4L) and Adenylate Kinase (AKe). Our strategy simultaneously exploits the structural and shape information contained in RDCs and the impossibility of domain inversion due to steric hindrance and covalent linkage. Exploiting the shape information contained in RDCs appears thus to be a promising strategy to determine how structural and dynamical information is transferred across multi-domain proteins.