Triplet repeat DNA structures and human genetic disease: dynamic mutations from dynamic DNA.
Fourteen genetic neurodegenerative diseases and three fragile sites have been associated with the expansion of (CTG)n (CAG)n, (CGG)n (CCG)n, or (GAA)n (TTC)n repeat tracts. Different models have been proposed for the expansion of triplet repeats, most of which presume the formation of alternative DNA structures in repeat tracts. One of the most likely structures, slipped strand DNA, may stably and reproducibly form within triplet repeat sequences. The propensity to form slipped strand DNA is proportional to the length and homogeneity of the repeat tract. The remarkable stability of slipped strand DNA may, in part, be due to loop-loop interactions facilitated by the sequence complementarity of the loops and the dynamic structure of three-way junctions formed at the loop-outs.
Sinden
Richard R
RR
Laboratory of DNA Structure and Mutagenesis, Center for Genome Research, Institute of Biosciences and Technology, Texas A&M University System Health Sciences Center, 2121 West Holcombe Blvd., Houston, TX 77030-3303, USA. Rsinden@IBT.TAMU.edu
Potaman
Vladimir N
VN
Oussatcheva
Elena A
EA
Pearson
Christopher E
CE
Lyubchenko
Yuri L
YL
Shlyakhtenko
Luda S
LS
D004247:DNA / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D018625:Microscopy, Atomic Force; D008957:Models, Genetic; D009154:Mutation; D019636:Neurodegenerative Diseases / Q000235:genetics*; D009690:Nucleic Acid Conformation; D019680:Trinucleotide Repeat Expansion; D018911:Trinucleotide Repeats
D004247:DNA