Fig. 3.

Native gel analysis of oligonucleotides containing wild-type or mutated CSB II. (A) Wt or G → A mutant RNA oligonucleotides (5 pmol total, of which 1.4 pmol labeled) were incubated overnight at 37 °C and separated on a 12% native gel. DNA size marker in the right-hand lane. bi-G4, bimolecular quadruplex; uni-G4, unimolecular quadruplex; asterisk denotes the more compact uni-G4* species. (B) RNA oligos (WT and mutant) were incubated in increasing concentrations of NaCl, LiCl, or KCl (0, 50, 150, or 1,000 mM) overnight at 37 °C. Reactions were separated on a 12% native gel. bi-G4, bimolecular quadruplex; uni-G4, unimolecular quadruplex; asterisk denotes a more compact G-quadruplex conformation. The arrow indicates the linear form of oligo, which is seen only with the mutant lacking the Gs required for quadruplex formation.