Capturing the Dynamics of a Spring-Loaded Protein.

Skp and other holdase chaperones bind unfolded bacterial outer membrane proteins, preventing premature folding until they insert into the membrane. In this issue of Structure, Holdbrook et al. (2017) use a combination of NMR, SAXS, ensemble optimization, and MD simulations to show that the Skp chaperone samples a much wider range of conformations than suggested by its structure alone.