Context dependence of trinucleotide repeat structures.

ABSTRACT: Long repeated sequences of DNA and their associated secondary structure govern the development and severity of a significant class of neurological diseases. Utilizing the effect of base stacking on fluorescence quantum yield, 2-aminopurine substitutions for adenine previously demonstrated sequestered bases in the stem and exposed bases in the loop for an isolated (CAG)(8) sequence. This study evaluates (CAG)(8) that is incorporated into a duplex, as this three-way junction is a relevant model for intermediates that lead to repeat expansion during DNA replication and repair. From an energetic perspective, thermally induced denaturation indicates that the duplex arms dictate stability and that the secondary structure of the repeated sequence is disrupted. Substitutions with 2-aminopurine pro

SUBMITTER: Degtyareva NN 

PROVIDER: S-EPMC6134211 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature