Interlocked mismatch-aligned arrowhead DNA motifs.

International audienceTriplet repeat sequences are of considerable biological importance as the expansion of such tandem arrays can lead to the onset of a range of human diseases. Such sequences can self-pair via mismatch alignments to form higher order structures that have the potential to cause replication blocks, followed by strand slippage and sequence expansion. The all-purine d(GGA)n triplet repeat sequence is of particular interest because purines can align via G.G, A.A and G.A mismatch formation