Figure 2.

Migration through a single-base heterology. (A) Negative winding shortened the tether, but the heterology prevented smooth migration. Once sufficient torque was built up, the heterologous base was ruptured and migration continued. Upon reverse winding, the heterologous base was easily wound through, resulting in a return to full basepairing. (Inset) Schematic depicting the sequence content; location relative to the extension and torque data is noted. (B) Rupture torque measurements were taken while winding the tether at different rates.