Related Experiment Video
Updated: Jul 19, 2025
08:28
Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
Published on: September 19, 2017
8.0K
Unveiling the structural mechanism of a G-quadruplex pH-Driven switch
Petra Galer1, Baifan Wang1, Janez Plavec2
1Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000, Ljubljana, Slovenia.
Biochimie
|August 12, 2023
Summary
The human telomere G-quadruplex (TAGGG) acts as a reversible pH-driven switch, forming distinct structures at different pH levels. This discovery aids in designing DNA-based nanomachines.
Area of Science:
- Biochemistry
- Structural Biology
- Nanotechnology
Background:
- Telomeres are protective caps at the ends of chromosomes.
- G-quadruplexes are non-canonical DNA structures with potential applications in nanotechnology.
- The human telomere oligonucleotide TAGGG is known to form G-quadruplex structures.
Purpose of the Study:
- To determine the high-resolution structures of the two pH-dependent forms of the human telomere G-quadruplex (TAGGG).
- To elucidate the structural features responsible for the pH-driven transformation.
- To explore the potential of TAGGG as a pH-sensitive DNA switch.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy to determine G-quadruplex structures.
- Computational techniques for structural analysis.
- Biophysical methods to study pH-induced structural changes.
Main Results:
- High-resolution structures of two distinct G-quadruplex forms (TD and KDH+) of TAGGG at pH 7.0 and 5.0 were determined.
- Unique loop architectures, base triples, and base pairs were identified as key determinants of the pH-driven structural transformation.
- TAGGG demonstrated a reversible pH-driven switch behavior, influenced by terminal residues and base triples.
Conclusions:
- TAGGG functions as a reversible pH-driven switch system.
- Understanding the factors regulating G-quadruplex formation and pH-sensitivity is crucial for designing DNA-based switches.
- This research opens avenues for developing novel DNA-based nanomachines and bio-nano-motors.
Related Concept Videos
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
2.3K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
2.3K
02:04Covalently Linked Protein Regulators
6.9K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
6.9K
01:12Mechanically-gated Ion Channels
6.4K
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
6.4K
01:48ATP Synthase: Mechanism
14.8K
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
14.8K
01:56Riboswitches
8.2K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
8.2K
01:03Single-Strand DNA Binding Proteins
14.2K
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
14.2K