Multi‐input CRISPR / C as genetic circuits that interface host regulatory networks

Genetic circuits require many regulatory parts in order to implement signal processing or execute algorithms in cells. A potentially scalable approach is to use dC as9, which employs small guide RNA s (sgRNAs) to repress genetic loci via the programmability of RNA : DNA base pairing. To this end, we use dC as9 and designed sgRNAs to build transcriptional logic gates and connect them to perform computation in living cells. We constructed a set of NOT gates by designing five synthetic Escherichia coli σ 70 promoters that are repressed by corresponding sgRNAs, and these interactions do not exhibit crosstalk between each other. These sgRNAs exhibit high on‐target repression (56‐ to 440‐fold) and negligible off‐target interactions (