Transposon Tn7 preferentially inserts into GAA*TTC triplet repeats under conditions conducive to Y*R*Y triplex formation.

ABSTRACT:

Background

Expansion of an unstable GAA*TTC repeat in the first intron of the FXN gene causes Friedreich ataxia by reducing frataxin expression. Structure formation by the repeat has been implicated in both frataxin repression and GAA*TTC instability. The GAA*TTC sequence is capable of adopting multiple non-B DNA structures including Y*R*Y and R*R*Y triplexes. Lower pH promotes the formation of Y*R*Y triplexes by GAA*TTC. Here we used the bacterial transposon Tn7 as an in vitro tool to probe whether GAA*TTC repeats can attract a well-characterized recombinase.

Methodology/principal findings

Tn7 showed a pH-dependent preference for insertion into uninterrupted regions of a Friedreich ataxia patient-derived repeat, inserting 48, 39 and 14 percent of the time at pH 7, pH 8 and

SUBMITTER: Mancuso M 

PROVIDER: S-EPMC2886061 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature