7JKU

Crystal structure of a four-tetrad, parallel, and K+ stabilized Tetrahymena thermophila telomeric G-quadruplex

7JKU の概要

• エントリーDOI: 10.2210/pdb7jku/pdb
• 分子名称: 26-mer DNA, POTASSIUM ION (3 entities in total)
• 機能のキーワード: g-quadruplex, parallel, four-quartets, propeller loops, dna
• 由来する生物種: Tetrahymena thermophila
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 8445.67

構造登録者

Yatsunyk, L.A.,McCarthy, S.E.,Beseiso, D.,Gallagher, E.P.,Chen, E.V.,Miao, J. (登録日: 2020-07-28, 公開日: 2021-07-07, 最終更新日: 2024-04-03)

主引用文献

Beseiso, D.,Chen, E.V.,McCarthy, S.E.,Martin, K.N.,Gallagher, E.P.,Miao, J.,Yatsunyk, L.A.
The first crystal structures of hybrid and parallel four-tetrad intramolecular G-quadruplexes.
Nucleic Acids Res., 50:2959-2972, 2022

PubMed Abstract: G-quadruplexes (GQs) are non-canonical DNA structures composed of stacks of stabilized G-tetrads. GQs play an important role in a variety of biological processes and may form at telomeres and oncogene promoters among other genomic locations. Here, we investigate nine variants of telomeric DNA from Tetrahymena thermophila with the repeat (TTGGGG)n. Biophysical data indicate that the sequences fold into stable four-tetrad GQs which adopt multiple conformations according to native PAGE. Excitingly, we solved the crystal structure of two variants, TET25 and TET26. The two variants differ by the presence of a 3'-T yet adopt different GQ conformations. TET25 forms a hybrid [3 + 1] GQ and exhibits a rare 5'-top snapback feature. Consequently, TET25 contains four loops: three lateral (TT, TT, and GTT) and one propeller (TT). TET26 folds into a parallel GQ with three TT propeller loops. To the best of our knowledge, TET25 and TET26 are the first reported hybrid and parallel four-tetrad unimolecular GQ structures. The results presented here expand the repertoire of available GQ structures and provide insight into the intricacy and plasticity of the 3D architecture adopted by telomeric repeats from T. thermophila and GQs in general.

PubMed: 35212369
DOI: 10.1093/nar/gkac091

実験手法

X-RAY DIFFRACTION (1.97 Å)