Multistate Structures and Dynamics at Atomic Resolution Using Exact Nuclear Overhauser Enhancements (eNOEs)
Biomolecules are highly dynamic systems comprising a complex interplay between motions covering several orders of magnitude in time that can be local or distant, and can be anticorrelated, random, or of concerted type. Understanding the relationship between motion and functions requires knowledge of the structure and dynamics at atomic resolution. However, the determined 3D structures of biomolecules are usually averaged snapshots of their conformational space or restricted to crystal packing and dynamics investigations mainly focusing on the time scale of motion. The recent advances in exact nuclear Overhauser enhancements (eNOEs) open an avenue for the ensemble-based structure determination of proteins on the basis of highly accurate quantitative ensemble-averaged distance restraints. In this chapter, the authors briefly describe the most recent progress in the applications of eNOEs for the calculation of multistate structural ensembles toward revealing the molecular mechanism of their activities. Among others, the implications of the exact NOEs to dissect protein allostery at atomic resolution and regulation of enzymatic activities are discussed. It appears that the eNOE methodology is a versatile tool in NMR-based structural biology to study the structure–dynamics–function relationship of biomacromolecules.