Analytical ultracentrifugation is a powerful tool to characterize interactions of macromolecules in solution. In sedimentation velocity experiments, the sedimentation of interaction partners and complexes can be monitored directly and can be used to characterize interactions quantitatively. As an example, we show how the interaction of the clamp loader subcomplex of DNA polymerase III from E. coli and a template/primer DNA saturated with single-stranded DNA-binding protein can be analyzed by analytical ultracentrifugation with fluorescence detection.
Keywords: Analytical ultracentrifugation; Clamp loader of DNA polymerase III; DNA replication; Fluorescence detection; Protein–DNA interaction; Sedimentation velocity experiments; Single-stranded DNA-binding protein (SSB); Sortase-mediated specific protein-labeling.