Figure 5. Single mRNA molecules can undergo conformational switching depending on their environment.

(a) Exemplary single-molecule trajectories from ligand-jump SiM-KARTS experiments composed of three time segments. Anti-SD probe binding to the same set of individual Tte mRNA molecules is monitored first in the absence of preQ₁ (Minus), then in the presence of 16 μM preQ₁ (Plus) and again in the absence of preQ₁ (Minus′). Each axis break represents a 50-s dark period between segments during which buffer was exchanged. (b) Distribution of burst density rankings for each segment of an individual molecule's trajectory, for all molecules in the ligand-jump SiM-KARTS experiment (N=97). (c) Rastergram displaying the bursting behaviour of the Tte mRNA molecules in b. Bursts are displayed as black bars. Individual probe-binding events (spikes) are omitted for clarity.