Another kind of dynamics: Ubiquitin noncovalently dimerizes with a dissociation constant of approximately 5mM. The two subunits adopt an array of relative orientations, utilizing an interface also for binding to other proteins (see picture). Quaternary fluctuation among members of the dimer ensemble constitutes a different kind of dynamics that complements the tertiary dynamics of each ubiquitin subunit.
- paramagnetic relaxation enhancement
- protein-protein interactions