7CLS
Solution structure of an intramolecular G-quadruplex containing a duplex bulge
Summary for 7CLS
| Entry DOI | 10.2210/pdb7cls/pdb |
| Descriptor | DNA (33-MER) (1 entity in total) |
| Functional Keywords | g-quadruplex, dna, quadruplex-duplex hybrid, bulge |
| Biological source | synthetic construct |
| Total number of polymer chains | 1 |
| Total formula weight | 10392.66 |
| Authors | Nguyen, T.Q.N.,Lim, K.W.,Phan, A.T. (deposition date: 2020-07-21, release date: 2020-09-30, Last modification date: 2024-05-15) |
| Primary citation | Ngoc Nguyen, T.Q.,Lim, K.W.,Phan, A.T. Duplex formation in a G-quadruplex bulge. Nucleic Acids Res., 48:10567-10575, 2020 Cited by 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: 32960213DOI: 10.1093/nar/gkaa738 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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