G Quadruplex Dna
G Quadruplex Dna - Related Videos
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.
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.
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.
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.
09:31
Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
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Cited by 56 •
2016
We describe a protocol for amplifying retroviral integration sites from the genomic DNA of infected cells, sequencing the amplified virus-host junctions, and then mapping these sequences to a reference genome. We also describe techniques to quantify the distribution of integration sites relative to various genomic annotations using BEDTools.
FAQs
Potassium ions occupy the central channel between stacked G-tetrads and help stabilize their arrangement. This ionic support is chemically important because the folded structure depends not only on guanine pairing but also on the cation environment. Consequently, changing the availability or identity of monovalent cations can influence whether a guanine-rich sequence maintains its G-quadruplex conformation.
Unlike the standard base-pairing arrangement associated with the double helix, guanines in a G-quadruplex use Hoogsteen hydrogen bonding to assemble into planar tetrads. Stacking several tetrads produces a compact folded arrangement with a cation-containing channel. This alternative geometry provides a structural basis for regulatory effects that cannot be explained by ordinary duplex DNA alone.
At telomeres and gene promoters, the biological consequence is linked to where the guanine-rich sequence occurs. A G-quadruplex in a promoter can influence transcription, whereas one in a telomeric region can relate to replication and genome stability. Thus, biochemists interpret the structure together with its genomic position rather than treating all quadruplexes as functionally equivalent.
Molecular probes and small molecules can be designed to selectively stabilize or disrupt G-quadruplex DNA. Comparing the effects of these agents helps researchers examine how the structure contributes to gene regulation, replication, or genome stability. In biochemistry, this approach connects a defined structural change with a possible biological consequence and supports investigation of G-quadruplexes as therapeutic targets.
Stabilization and disruption represent contrasting ways to examine the role of a G-quadruplex. Maintaining the folded structure can test effects associated with its persistence, while disrupting it can examine outcomes when that structure is reduced. Comparing these opposing interventions helps researchers relate structural state to processes such as transcription, replication, and genome stability.
G-quadruplex DNA links molecular interactions with larger biological outcomes. Guanine hydrogen bonding, tetrad stacking, and cation stabilization produce a structure that can participate in gene regulation, replication, and genome stability. Studying these connections gives biochemists a framework for analyzing noncanonical DNA behavior and for developing selective probes or small molecules for research and therapeutic applications.