Figure 5.

Examples of small-molecule control of engineered gRNAs. (A) gRNAs are fused with an aptamer that is unstructured, but are stabilized and folded into a functional form by binding to theophylline. (B) gRNAs are fused with an aptazyme that is activated by binding to theophylline and induces the RNA self-cleavage to release functional gRNAs. (C) Mutant gRNAs containing G-G mismatches are recognized and inactivated by NCD. (D) A gRNA masked with AMN groups becomes activated by reacting with phosphines. (E) Active gRNAs that contain small chemical modifications become inactive by the binding or reaction with larger moieties.