Part:BBa_K2970002

Gate

This gate is a toehold switch system with which a gene of interest can be locked and regulated on a translational level using mRNA as regulator. After transcription, the mRNA of this gate forms a hairpin that hides the ribosome binding site and start codon of the gene of interest, thus translation can not occur (Figure 1B). A complementary part to the gate, a so called trigger, is needed to open the hairpin and release the ribosome binding site. In this case two triggers are needed that form a trigger complex to open the gate (BBa_K2970000 and BBa_K2970001). The affinity between the trigger complex and the gate is greater than that of the gate to itself (in the loop). A single trigger cannot open the gate because it has only half the required complementary sequence.

Figure 1: A) Formation of trigger complex after translation. B) mRNA of gate sequence forms secondary structures that hide the ribosome binding site and the start codon.

Figure 2: Opening of the gate due to annealing of trigger complex to gate.

To transform this part into bacteria it should be put on a plasmid together with a promoter and a terminator. We used this part to regulate a chloramphenicol resistance gene that we put behind the gate (BBa_K2970006).

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]