Figure 2.

The key DNA components involved in the DNA circuit are shown in terms of their domain specifications. Initiator 1 (I1) and initiator 2 (I2) were bound to α-thrombin via domain ‘a1’ and ‘a2’ Domain ‘t*’ and ‘b*’ are ‘keys’ initiating the signal transduction and HCR process, respectively. Domain ‘c’ and ‘c*’ represents the HCR hairpin stem; while domain ‘b’ and ‘d’ are alternating toeholds mediating the HCR process. A spacer (‘s’) domain was included to signify the possibility of probing over separation distances up to ca. 30 nm by varying its sequence length.