The sequence specificity of Rap1 binding to telomeric DNA. The impact of single-nucleotide substitutions on the binding ability of (A) scasRap1-DBD and (B) full-length scasRap1 was analyzed by EMSA competitions. The fraction of labeled wild-type probe still bound at an excess of non-labeled mutated competitor is depicted for each mutated position. A high value means that the position is important for the sequence-specific binding. Note that the absolute values should only be compared within the same graph. The wild-type oligonucleotide Scast14C (numbered sequence at the bottom of the graphs) was included in each gel and used to normalize the signal.