Fig. 3.

Single molecule FRET histograms for HTIQ. (A) From top to bottom, all in 10 mM NaCl and 10 mM Tris–HCl (pH 7.4), at 7 °C, 20 °C, 43 °C, and 43 °C with additional 10 mM KCl. (B) From top to bottom, all in 10 mM Tris–HCl (pH 7.4), at 20 °C, 100 mM NaCl; at 37 °C, 100 mM NaCl; at 20 °C 100 mM KCl; and at 37 °C, 100 mM KCl. Solid curves are the best fit to guassian functions. The “zero” peaks, largely due to inactive Cy5, have been subtracted for clarity. Copyright (2003) National Academy of Sciences of the United States of America [57].