%0 Journal Article %A Adrian, Michael %A Ang, Ding Jie %A Lech, Christopher J. %A Heddi, Brahim %A Nicolas, Alain %A Phan, Anh Tuân %D 2014 %T Structure and Conformational Dynamics of a Stacked Dimeric G‑Quadruplex Formed by the Human CEB1 Minisatellite %U https://acs.figshare.com/articles/journal_contribution/Structure_and_Conformational_Dynamics_of_a_Stacked_Dimeric_G_Quadruplex_Formed_by_the_Human_CEB1_Minisatellite/2302123 %R 10.1021/ja4125274.s001 %2 https://acs.figshare.com/ndownloader/files/3939709 %K Conformational Dynamics %K NMR solution structure %K Human CEB 1 MinisatelliteCEB 1 %K size variation %K DNA %K CEB 1 tandem arrays %K millisecond time scale %K subunit %K sequence forms %K minisatellite %K loop %X CEB1 is a highly polymorphic human minisatellite. In yeast, the size variation of CEB1 tandem arrays has been associated with the capacity of the motif to form G-quadruplexes. Here we report on the NMR solution structure of a G-quadruplex formed by the CEB1 DNA G-rich fragment d­(AGGGGGGAGGGAGGGTGG), harboring several G-tracts including one with six continuous guanines. This sequence forms a dimeric G-quadruplex involving the stacking of two subunits, each being a unique snapback parallel-stranded scaffold with three G-tetrad layers, three double-chain-reversal loops, and a V-shaped loop. The two subunits are stacked at their 5′-end tetrads, and multiple stacking rotamers may be present due to a high symmetry at the stacking interface. There is a conformational exchange in the millisecond time scale involving a swapping motion between two bases of the six-guanine tract. Our results not only add to the understanding of how the G-quadruplex formation in human minisatellite leads to genetic instability but also address the fundamental questions regarding stacking of G-quadruplexes and how a long continuous G-tract participates in the structure and conformational dynamics of G-quadruplexes. %I ACS Publications