Small molecule-induced trinucleotide repeat contractions during DNA synthesis

We demonstrated that a synthetic ligand NA, which selectively binds to a 5′-CAG-3′/5′-CAG-3′ triad, induced repeat contractions during DNA polymerase-mediated primer extension through the CAG repeat template. A thorough capillary electrophoresis and sequencing analysis revealed that the d(CAG) 20 template gave shortened nascent strands mainly containing 3-6 CTG units in the presence of NA. A CAG repeat binding molecule, NA, induced efficient repeat contractions during DNA polymerase-mediated primer extension through a CAG repeat template.