Figure 5.
Sequence requirements of G-quadruplex tetramer formation. (A) Heat map showing the ability of all possible variants of the central tetrad of the reference construct to form tetramers at 10 μM DNA concentration. (B) DNA concentration at which tetramer formation is half the maximum value (K0.5) for 11 of the variants identified in our screen. (C) Native gel and graph showing tetramer formation as a function of DNA concentration. Experiments in panel (C) were performed using a construct with a GGAG mutation in the central tetrad of the reference construct and the sequence GGGTGGGAAGAGTGGGA. Experiments were typically performed between 10 nM and 10 μM G-quadruplex concentration in a buffer containing 200 mM KCl, 1 mM MgCl2 and 20 mM HEPES pH 7.1.