Binding between G Quadruplexes at the Homodimer Interface of the Corn RNA Aptamer Strongly Activates Thioflavin T Fluorescence

Thioflavin T (ThT) is widely used for the detection of amyloids. Many unrelated DNAs and RNAs that contain G-quadruplex motifs also bind ThT and strongly activate its fluorescence. To elucidate the structural basis of ThT binding to G quadruplexes and its fluorescence turn-on, we determined its co-crystal structure with the homodimeric RNA Corn, which contains two G quadruplexes. We found that two ThT molecules bind in the dimer interface,...