BIOPHYSICS, CHEMISTRY. For the article “Watching proteins fold one molecule at a time,” by Elizabeth Rhoades, Eugene Gussakovsky, and Gilad Haran, which appeared in issue 6, March 18, 2003, of Proc. Natl. Acad. Sci. USA (100, 3197–3202; First Published February 28, 2003; 10.1073/pnas.2628068100), the locants for Fig. 6 on page 3201 were incorrect. Locant C should have appeared as B, E should have appeared as C, B should have appeared as D, and D should have appeared as E. The corrected figure and its legend appear below.
Fig. 6.
Time-dependent signals from single molecules showing slow folding or unfolding transitions. (A) Signals showing a slow folding transition starting at ≈0.5 sec and ending at ≈2 sec. The same signals display a fast unfolding transition as well (at ≈3 sec). The acceptor signal is shown in red, and the donor is shown in green. (B) EET trajectory calculated from the signals in A. (C) The interprobe distance trajectory showing that the slow transition involves a chain compaction by only 20%. The distance was computed from the curve in B (32) by using a Förster distance (R0) of 49 Å. This Förster distance was calculated by assuming an orientational factor (κ2)of2/3. However, the point discussed here (and in the text) does not depend on the exact value of κ2 or R0.(D–F) Additional EET trajectories demonstrating slow transitions. These transitions were identified, as already noted, by anticorrelated donor-acceptor intensity changes.