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Updated: May 20, 2026
08:28
Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
Published on: September 19, 2017
Topological rules and anomalies in intramolecular G-quadruplex folding: a comprehensive study
Anton Granzhan1, Liliane Mouawad2
1Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (LCBPT), CNRS UMR8601, Université Paris Cité, Paris 75006, France.
Nucleic Acids Research
|May 19, 2026
Summary
G-quadruplexes (G4s) form complex structures in DNA and RNA. This study reveals key folding rules governing G4 topology based on loop length, clarifying how different structures form.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- G-quadruplexes (G4s) are nucleic acid structures with diverse topologies.
- The folding rules dictating G4 topology remain incompletely understood.
Purpose of the Study:
- To systematically investigate the folding rules of intramolecular G-quadruplexes.
- To establish the relationship between loop length and G4 topology.
Main Methods:
- Analysis of 353 intramolecular G-quadruplex structures.
- Correlation of loop lengths with observed G4 topologies.
Main Results:
- Loop length dictates G4 topology: parallel G4s form with one-nucleotide loops.
- Specific loop length combinations determine parallel, antiparallel-chair, or antiparallel-basket topologies.
- Diagonal loops require at least 4 nucleotides; only three topologies accommodate them.
Conclusions:
- Established folding principles for G-quadruplexes based on topological restraints.
- Explained preferential formation of parallel/hybrid versus antiparallel G4s based on tetrad number.
- Clarified requirements for bulges in quadruplex-duplex hybrids.
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