The effect of the TRF2 N-terminal and TRFH regions on telomeric G-quadruplex structures.

ABSTRACT: The sequence of human telomeric DNA consists of tandem repeats of 5'-d(TTAGGG)-3'. This guanine-rich DNA can form G-quadruplex secondary structures which may affect telomere maintenance. A current model for telomere protection by the telomere-binding protein, TRF2, involves the formation of a t-loop which is stabilized by a strand invasion-like reaction. This type of reaction may be affected by G-quadruplex structures. We analyzed the influence of the arginine-rich, TRF2 N-terminus (TRF2(B)), as well as this region plus the TRFH domain of TRF2 (TRF2(BH)), on the structure of G-quadruplexes. Circular dichroism results suggest that oligonucleotides with 4, 7 and 8 5'-d(TTAGGG)-3' repeats form hybrid structures, a mix of parallel/antiparallel strand orientation, in K(+). TRF2(B) stimulated th

SUBMITTER: Pedroso IM 

PROVIDER: S-EPMC2655686 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature