School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
NTU Institute of Structural Biology, Nanyang Technological University, Singapore, 636921, Singapore.
Angew Chem Int Ed Engl. 2019 Sep 23;58(39):13834-13839. doi: 10.1002/anie.201907740. Epub 2019 Aug 21.
A knot-like G-quadruplex peripheral structure is formed by a 7-nt DNA sequence DL7 (TGTTGGT), in which six out of its seven nucleobases participate in compact base-pairing interactions. Here, the solution NMR structure of a 24-nt DNA oligonucleotide containing the DL7 sequence shows the interaction between a two-layer anti-parallel G-quadruplex core and the peripheral knot-like structure, including the construction of two sharp turns in the DNA backbone. The formation of this novel structural element highlights the intricate properties of single-stranded DNA folding in presence of G-quadruplex-forming motifs. We demonstrated the compatibility of the DL7 knot-like structure with various G-quadruplexes, which could have implications in drug design and DNA engineering.
一个由 7 个核苷酸组成的 DNA 序列 DL7（TGTTGGT）形成了一个类似结的 G-四链体外围结构，其中七个核苷酸中的六个参与了紧凑的碱基配对相互作用。在这里，包含 DL7 序列的 24 个核苷酸 DNA 寡核苷酸的溶液 NMR 结构显示了双层反平行 G-四链体核心与外围类似结结构之间的相互作用，包括 DNA 骨架中两个急转弯的构建。这种新型结构元件的形成突出了单链 DNA 在形成 G-四链体基序时折叠的复杂特性。我们证明了 DL7 类似结结构与各种 G-四链体的兼容性，这可能对药物设计和 DNA 工程具有重要意义。
