The Fragile-X peptide-aptamer RNA and DHX36-c-Myc complexes. (A) Cartoon representation of the three-dimensional structure of the RGG-Sc1 complex (PDB:5DE5; Vasilyev et al. 2015). The location of the mixed-sequence quartet is indicated. The RGG peptide is highlighted by its translucent molecular surface. (B) Schematic of the Sc1 quadruplex. (C) Hydrogen bond and coordination network of the mixed-sequence quartet of Sc1. The RGG peptide abuts this quartet. Red and purple spheres depict water molecules and K+, respectively. (D) Cartoon representation of the c-Myc quadruplex bound to the amino-terminal α-helix (DSM) of DHX36 (PDB:5VHE; Chen et al. 2018). (E) Schematic of the c-Myc quadruplex bound to DHX36. (F) Detail of the mixed-sequence quartet.
