title: Trinucleotide repeats that expand in human disease form hairpin structures in vitro.
abstract: We show that repeating units from all reported disease genes are capable of forming hairpins of common structure and threshold stability. The threshold stability is roughly -50 kcal per hairpin and is influenced by the flanking sequence of the gene. Hairpin stability has two components, sequence and length; only DNA of select sequences and the correct length can form hairpins of threshold energy. There is a correlation among the ability to form hairpins of threshold stability, the sequence selectivity of expansion, and the length dependence of expansion. Additionally, hairpin formation provides a potential structural basis for the constancy of the CCG region of the Huntington's disease gene in individuals and explains the stabilizing effects of AGG interruptions in FMR1 alleles.
authors.affiliation: Mayo Foundation and Graduate School, Rochester, Minnesota, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Gacy
authors.forename: G
authors.initials: G
authors.lastname: Goellner
authors.forename: N
authors.initials: N
authors.lastname: Juranić
authors.forename: S
authors.initials: S
authors.lastname: Macura
authors.forename: C T
authors.initials: CT
authors.lastname: McMurray
mesh_terms: D001483:Base Sequence; D030342:Genetic Diseases, Inborn / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D017421:Sequence Analysis