Lambda exonuclease digestion of CGG trinucleotide repeats.
Fragile X syndrome and other trinucleotide diseases are characterized by an elongation of a repeating DNA triplet. The ensemble-averaged lambda exonuclease digestion rate of different substrates, including one with an elongated FMR1 gene containing 120 CGG repeats, was measured using absorption and fluorescence spectroscopy. By use of magnetic tweezers sequence-dependent digestion rates and pausing was measured for individual lambda exonucleases. Within the triplet repeats a lower average and narrower distribution of rates and a higher frequency of pausing was observed.
Conroy
R S
RS
Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA. conroyri@mail.nih.gov
Koretsky
A P
AP
Moreland
J
J
D000042:Absorption; D010584:Bacteriophage phi X 174; D005092:Exonucleases / Q000737:chemistry*; D005453:Fluorescence; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000737:chemistry* / Q000235:genetics*; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013997:Time Factors; D018911:Trinucleotide Repeats
D005092:Exonucleases; D051860:Fragile X Messenger Ribonucleoprotein 1