2MB4

Solution structure of a stacked dimeric G-quadruplex formed by a segment of the human CEB1 minisatellite

Summary for 2MB4

• Entry DOI: 10.2210/pdb2mb4/pdb
• NMR Information: BMRB: 19389
• Descriptor: DNA_(5'-D(*AP*GP*GP*GP*GP*GP*GP*AP*GP*GP*GP*AP*GP*GP*GP*TP*GP*G)-3') (1 entity in total)
• Functional Keywords: g-quadruplex, stacking, ceb1, minisatellite, dna
• Total number of polymer chains: 2
• Total formula weight: 11615.48

Authors

Adrian, M.,Ang, D.J.,Lech, C.,Heddi, B.,Nicolas, A.,Phan, A.T. (deposition date: 2013-07-25, release date: 2014-05-28, Last modification date: 2024-05-15)

Primary citation

Adrian, M.,Ang, D.J.,Lech, C.J.,Heddi, B.,Nicolas, A.,Phan, A.T.
Structure and Conformational Dynamics of a Stacked Dimeric G-Quadruplex Formed by the Human CEB1 Minisatellite.
J.Am.Chem.Soc., 136:6297-6305, 2014

PubMed Abstract: 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.

PubMed: 24742225
DOI: 10.1021/ja4125274

Experimental method

SOLUTION NMR