Kim, J. et al. De novo-designed translation-repressing riboregulators for multi-input cellular logic. Nat. Chem. Biol. 15, 1173–1182 (2019).
In this publication, Kim and colleagues design and characterize two types of riboregulators: Toehold Switch repressors nad three-way-junction (3WJ) repressors. Both are based on occlusion of the ribosome binding site (RBS) by RNA secondary structure. A trans-repressing RNA triggers a change of structure that either promotes the folding of a hairpin (Toehold Switches) or promotes the tightening of a hairpin (3WJ), occluding the RBS. The ones picked for the repository are the ones reported to be orthogonal, and the Toehold Switches with the highest reported dynamic ranges (2, 19, 64 and 72). Multi-input AND and OR gates have shown to work with these parts.
There are US and WO patents claiming intellectual propety over the sequences.