Figure 1.
Schematic representation of G4 motif. (A) Hydrogen-bonded G-tetrad with K+ (Na+ also stabilizes a G-tetrad); each guanine in this planar array is contributed from different G-runs, which are separated by intervening loops in an intramolecular motif. (B,C) Intramolecular folding pattern showing stem and loop organization in an antiparallel (B) and parallel (C) conformation of a G4 motif, where the planes represent each tetrad unit and are stacked to form the stem of the motif.
