Overexpression of the single-stranded DNA-binding protein (SSB) stabilises CAG*CTG triplet repeats in an orientation dependent manner.
The stability and deletion-size-distribution profiles of leading strand (CAG)(75) and (CTG)(137) trinucleotide repeat arrays inserted in the Escherichia coli chromosome were investigated upon overexpression of the single-stranded DNA-binding protein (SSB) and in mutant strains deficient for the SbcCD (Rad51/Mre11) nuclease. SSB overexpression increases the stability of the (CAG)(75) repeat array and leads to a loss of the bias towards large deletions for the same array. Furthermore, the absence of SbcCD leads to a reduction in the number of large deletions in strains containing the (CTG)(137) repeat array.
Andreoni
Federica
F
Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
Darmon
Elise
E
Poon
Wilson C K
WC
Leach
David R F
DR
D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005092:Exonucleases / Q000235:genetics; D042822:Genomic Instability; D017384:Sequence Deletion; D018911:Trinucleotide Repeats / Q000235:genetics*
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C476430:SSB protein, E coli; C489229:SbcC protein, E coli; D003851:Deoxyribonucleases; D005092:Exonucleases; C081229:sbcD protein, E coli