What Nuclear Magnetic Resonance can tell us about Proteins: Application to a Folding Scaffold and its Targets

Proteins are complex polymers consisting of thousands of atoms. Out of the many possible conformations of such a molecule, usually only a few or perhaps just one (the "native" conformation) is significantly populated. Proteins interact extensively to form complexes, but in precisely defined ways. Both proper folding and proper specificity of interaction are essential for biological function. Nuclear Magnetic Resonance (NMR) is a powerful tool for the study of protein conformations and interactions. NMR-measurable parameters are sensitive probes of the chemical environment and dynamic behavior of nucleii. Unlike most other biophysical techniques, NMR is capable of atomic resolution, making measurements on single atoms in proteins consisting of thousands. NMR is non-invasive, involving only the very small energies needed to perturb the nuclear spin system and leaving chemical equilibrium essentially untouched. In this presentation I will review the insights gained through NMR into the biophysics of LC8, a ubiquitous protein found in many types of organism, originally discovered as part of the Dynein molecular motor and now known to be a part of diverse protein complexes. The emerging view of LC8 is that it acts as a scaffold for larger protein complexes by bringing together pairs of its binding partners.