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Updated: Nov 8, 2025
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
964
Recurrent Potential G-Quadruplex Sequences in Archaeal Genomes
Galina V Chashchina1,2, Anna K Shchyolkina1, Simon V Kolosov2
1Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
Frontiers in Microbiology
|April 19, 2021
Summary
Repetitive G-quadruplex sequences (rPQS) in archaea form G4 structures but also alternative DNA folds. Their genomic context suggests potential functional roles beyond simple G4 formation.
Area of Science:
- Genomics
- Biochemistry
- Molecular Biology
Background:
- Evolutionary conservation of potential G-quadruplex sequences (PQS) suggests function, but GC-content bias can create false positives.
- Identifying functional PQS requires distinguishing true signals from genomic biases and other conserved elements.
Purpose of the Study:
- To investigate the functional relevance of repetitive PQS (rPQS) in archaeal genomes.
- To analyze the structure and genomic context of rPQS to infer their potential roles.
Main Methods:
- Genome analysis of archaea, specifically focusing on repetitive PQS motifs.
- Circular dichroism (CD) and enzymatic probing to confirm G-quadruplex (G4) formation.
- Analysis of adjacent genomic sequences, including cytosine-rich tracks.
Main Results:
- Multiple highly similar rPQS were found in Methanomicrobiaceae archaea.
- Oligonucleotides corresponding to rPQS formed G4 structures in the presence of potassium ions.
- A cytosine-rich track adjacent to rPQS influenced DNA folding into alternative structures like hairpins and triplexes, in equilibrium with G4.
Conclusions:
- Repetitive PQS in archaea exhibit complex structural behavior influenced by adjacent sequences.
- The interplay between G4, hairpin, and triplex structures suggests sophisticated regulatory roles.
- Genomic location and structural plasticity of rPQS point towards functional significance in archaeal genomes.
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