G-quadruplex Structures
G-quadruplex Structures - Related Videos
05:32
In Vitro Chemical Mapping of G-Quadruplex DNA Structures by Bis-3-Chloropiperidines
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2023
Bis-3-chloropiperidines (B-CePs) are useful chemical probes to identify and characterize G-quadruplex structures in DNA templates in vitro. This protocol details the procedure to perform probing reactions with B-CePs and to resolve reaction products by high-resolution polyacrylamide gel electrophoresis.
11:25
A G-quadruplex DNA-affinity Approach for Purification of Enzymatically Active G4 Resolvase1
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Cited by 6 •
2017
G4 Resolvase1 binds to G-quadruplex (G4) structures with the tightest reported affinity for a G4-binding protein and represents the majority of the G4-DNA unwinding activity in HeLa cells. We describe a novel protocol that harnesses the affinity and ATP-dependent unwinding activity of G4-Resolvase1 to specifically purify catalytically active recombinant G4R1.
08:28
Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
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Cited by 4 •
2017
A single-molecule magnetic tweezers platform to manipulate G-quadruplexes is reported, which allows for the study of G4 stability and regulation by various proteins.
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
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2025
This protocol outlines a fluorescence microscopy-based single-molecule DNA replication assay, enabling real-time visualization of interactions between DNA polymerases and obstacles such as G-quadruplex structures.
03:38
Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction
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Cited by 1 •
2022
The present protocol demonstrates the use of a fast, 3-stage, aptamer-based exponential amplification assay to detect targets. Sample preparation, signal amplification, and color development are covered to implement this system to recognize the presence of theophylline over that of caffeine.
FAQs
Monovalent cations, particularly potassium, stabilize stacked G-quartets by occupying the central position within the structure. Hoogsteen hydrogen bonds hold the guanine bases in each planar quartet, while cation support helps maintain the four-stranded configuration. Because formation is reversible, changes in structural stability can influence when a sequence affects replication, transcription, or translation.
Reversibility makes these structures dynamic regulators rather than permanent architectural features. A guanine-rich sequence can adopt or release the configuration, allowing its influence on genome organization, replication, transcription, or translation to vary in biological settings. This property also makes G-quadruplex structures useful for examining how structural changes are coupled to gene regulation and genome stability.
The biological consequence depends partly on where a structure forms. At telomeres, G-quadruplexes are relevant to genome stability; in promoter regions, they can affect transcription; and in RNA transcripts, they can influence translation. Considering sequence location therefore connects the same structural principle to distinct regulatory processes rather than treating all occurrences as functionally equivalent.
An analysis should account for guanine-rich DNA or RNA, Hoogsteen-linked G-quartets, stacked quartets, and a central monovalent cation such as potassium. It should also consider proteins and small molecules that recognize these structures. Together, these components provide a framework for relating structural formation to regulation and for interpreting whether a biological effect may be reversible.
Recognition by specific proteins and small molecules gives researchers a way to examine how these structures participate in cellular regulation. Such interactions can be studied in relation to telomeres, promoters, or RNA transcripts, where the biological relevance includes genome stability, transcription, and translation. This makes quadruplex recognition important both for basic biology and for exploring therapeutic strategies.
Their reversible formation and recognition by proteins and small molecules make G-quadruplex structures valuable subjects for therapeutic investigation. These properties connect a defined nucleic-acid configuration with replication, transcription, translation, and genome stability. Therapeutic interest therefore arises from their regulatory position in cells, not simply from their unusual four-stranded architecture.