Figure 2.
tP5abc collapses with increasing ionic strength. (A) The extended state secondary structure of tP5abc.19 The A186U mutation is indicated with an arrow. (B) tP5abc extended state conformation in solution,20 shown with the same color scheme as in (A). (C, D) Diffusion times of A186U mutant obtained from FCS measurements in K+ and Mg2+, respectively. A dramatic decrease in τD is observed upon the addition of salt, demonstrating tP5abc compaction with the increase in bulk counterion concentration.