Figure 2.

The C-rich sequence associated with a meiosis-specific DSB on chromosome IV of S. cerevisiae folds into an intramolecular i-motif. (A) Shown here are the nucleotide sequences of C-rich WT, C-MT, and poly (dT). The C-residues are highlighted in red. The C to T substitution in the mutant sequence is denoted by green. (B) Shown here is the EMSA analysis of i-motif structures formed by increasing concentrations of a ³²P-labeled poly(dT), C-mutant, and C-rich WT ODNs in a 50 mM sodium phosphate buffer (pH 5.5). The solid triangle on top of the gel image denotes increasing concentrations of the indicated ODN. Lanes 1–4 contain 50, 100, 150, and 200 nM poly(dT), lanes 5–8 contain 50, 100, 150, and 200 nM C-mutant, and lanes 9–12 contain 50, 100, 150, and 200 nM C-rich WT ODN, respectively. (C) Shown here is the effect of pH on the formation of i-motif by C-rich WT ODN. (D) Shown here is the effect of pH on the formation of i-motif by C-mutant ODN.