Part:BBa_K5106007

2 input AND gate for the detection of a dimerised miRNA trigger

This AND gate is designed for the detection of multiple RNAs in combination. The toehold switch will be activated only if two specific miRNAs are present. It can be used to detect multiple disease-specific miRNAs to increase the accuracy of the test.

Usage and Biology

A 2-input AND gate is a single toehold switch that gets activated by two trigger RNAs. The input for the respective toehold switch is a combination of two input RNA molecules that are partially complimentary to each other. These partially complementary inputs hybridize to form an input trigger RNA that can anneal to the trigger binding region of the toehold switch. Once the trigger RNA is bound to the trigger binding region, the loop in the toehold switch opens up and the RBS is available for the ribosome to bind, allowing gene expression (Figure 1). The absence of any one trigger RNA will not lead to the unfolding of the loop structure, thus causing no gene translation. This switch was deigned by Green et al. 2017.¹

Figure 1: Simplified mechanism of a toehold AND gate. Two different trigger RNA, which are partially complementary, hybridise together. This complex then acts as input trigger RNA for the toehold switch, by annealing to the trigger binding region of the toehold switch, allowing the hairpin to linearize. This allows for binding of the ribosome and translation of the repressed mRNA.

For experimental data of this part, see composite part BBa_K5106010, where the part is tested in a cell-free (PURExpress) system, under a T7 promoter and terminator, and regulating the LacZ reporter gene. For more details on the use of this part, take a look at miRADAR (WageningenUR 2024).

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]

References

1. Green, Alexander A., Jongmin Kim, Duo Ma, Pamela A. Silver, James J. Collins, and Peng Yin. ‘Complex Cellular Logic Computation Using Ribocomputing Devices’. Nature 548, no. 7665 (August 2017): 117–21. https://doi.org/10.1038/nature23271.