7CLS

Solution structure of an intramolecular G-quadruplex containing a duplex bulge

7CLS の概要

• エントリーDOI: 10.2210/pdb7cls/pdb
• 分子名称: DNA (33-MER) (1 entity in total)
• 機能のキーワード: g-quadruplex, dna, quadruplex-duplex hybrid, bulge
• 由来する生物種: synthetic construct
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 10392.66

構造登録者

Nguyen, T.Q.N.,Lim, K.W.,Phan, A.T. (登録日: 2020-07-21, 公開日: 2020-09-30, 最終更新日: 2024-05-15)

主引用文献

Ngoc Nguyen, T.Q.,Lim, K.W.,Phan, A.T.
Duplex formation in a G-quadruplex bulge.
Nucleic Acids Res., 48:10567-10575, 2020

PubMed Abstract: Beyond the consensus definition of G-quadruplex-forming motifs with tracts of continuous guanines, G-quadruplexes harboring bulges in the G-tetrad core are prevalent in the human genome. Here, we study the incorporation of a duplex hairpin within a bulge of a G-quadruplex. The NMR solution structure of a G-quadruplex containing a duplex bulge was resolved, revealing the structural details of the junction between the duplex bulge and the G-quadruplex. Unexpectedly, instead of an orthogonal connection the duplex stem was observed to stack below the G-quadruplex forming a unique quadruplex-duplex junction. Breaking up of the immediate base pair step at the junction, coupled with a narrowing of the duplex groove within the context of the bulge, led to a progressive transition between the quadruplex and duplex segments. This study revealed that a duplex bulge can be formed at various positions of a G-quadruplex scaffold. In contrast to a non-structured bulge, the stability of a G-quadruplex slightly increases with an increase in the duplex bulge size. A G-quadruplex structure containing a duplex bulge of up to 33 nt in size was shown to form, which was much larger than the previously reported 7-nt bulge. With G-quadruplexes containing duplex bulges representing new structural motifs with potential biological significance, our findings would broaden the definition of potential G-quadruplex-forming sequences.

PubMed: 32960213
DOI: 10.1093/nar/gkaa738

実験手法

SOLUTION NMR