AND gate

In order to integrate the first and second memory unit, we designed the AND gate system. In the second occurrence, the first memory unit runs, the AND gate activates the second memory unit. To modulate gene expression at the translation level, we harness the use of engineered RNA-based/riboregulator system. After transcription, the 5’ UTR of crRNA-LasR transcript will form a stem-loop structure that blocks the RBS and prevents translation. To activate the expression of a self-repressed gene, the taRNA which is complementary to crRNA will unfold the stem-loop structure thus exposing the obstructed RBS and permit translation. (Isaacs, 2006)

The design of the AND gate circuit is based on two constructs, noncoding taRNA-DT cloned downstream of a hybB promoter (PhybB) and a cI promoter (PcI) cloned upstream crRNA-RBS-LasR-TAG-DT. In attempt to characterize the functional assembled parts, we cotransformed plasmid harboring AND gate system with reporter plasmid downstream LasR promoter.