Figure EV1. Static dsDNA control experiments.

1. Schematic representation of the smFRET assay using labeled double‐stranded DNA with Alexa 555 and Cy5 fluorophores as indicated. Distance estimates can be derived by multiplication of 0.34 nm times the number of base pairs; these provide only an inaccurate approximation of the distance between donor and acceptor dye.
2. Experimental data similar to those shown in Fig 2 are shown, which support the validity of experimental results and interpretations given in the main text.