7V6V

trimolecular G-quadruplexes consists of a hairpin motif and two short chains

Summary for 7V6V

• Entry DOI: 10.2210/pdb7v6v/pdb
• Descriptor: DNA (5'-D(*CP*AP*GP*GP*GP*AP*GP*GP*GP*T)-3'), DNA (5'-D(*TP*GP*GP*GP*A)-3') (2 entities in total)
• Functional Keywords: g-quadruplex, hybrid strands, trimolecular, dna
• Biological source: Homo sapiens; More
• Total number of polymer chains: 3
• Total formula weight: 6270.18

Authors

Zhang, N.,Jing, H.T.,Hu, W.X. (deposition date: 2021-08-20, release date: 2023-02-08, Last modification date: 2024-05-15)

Primary citation

Hu, W.,Jing, H.,Fu, W.,Wang, Z.,Zhou, J.,Zhang, N.
Conversion to Trimolecular G-Quadruplex by Spontaneous Hoogsteen Pairing-Based Strand Displacement Reaction between Bimolecular G-Quadruplex and Double G-Rich Probes.
J.Am.Chem.Soc., 2023

PubMed Abstract: Bimolecular or tetramolecular G-quadruplexes (GQs) are predominantly self-assembled by the same sequence-identical G-rich oligonucleotides and usually remain inert to the strand displacement reaction (SDR) with other short G-rich invading fragments of DNA or RNA. Appealingly, in this study, we demonstrate that a parallel homomeric bimolecular GQ target of d(CAGGGAGGGT) as the starting reactant, although completely folded in K solution and sufficiently stable (melting temperature of 57.7 °C), can still spontaneously accept strand invasion by a pair of short G-rich invading probes of d(TGGGA) near room temperature. The final SDR product is a novel parallel heteromeric trimolecular GQ (tri-GQ) of reassembled between one strand and two strands. Here we present, to the best of our knowledge, the first NMR solution structure of such a discrete heteromeric tri-GQ and unveil a unique mode of two probes vs one target in mutual recognition among G-rich canonical DNA oligomers. As a model system, the short invading probe can spontaneously trap G-rich target from a Watson-Crick duplex completely hybridized between and its fully complementary strand d(ACCCTCCCTG). The sequence of d(CAGGGAGGGT) is a fragment from the G-rich promoter region of the human β2-tubulin gene. Our findings provide new insights into the Hoogsteen pairing-based SDR between a GQ target and double invading probes of short G-rich DNA fragments and are expected to grant access to increasingly complex architectures in GQ-based DNA nanotechnology.

PubMed: 37553999
DOI: 10.1021/jacs.3c05617

Experimental method

SOLID-STATE NMR