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Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
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Non-Random Distribution of G-Quadruplex Structures Reveals Regulatory and Ecological Adaptations in Bacterial Genomes
1State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
International Journal of Molecular Sciences
|October 29, 2025
Summary
G-quadruplexes (G4s), guanine-rich DNA structures, are found in bacteria, particularly near gene start sites. Their density varies with environment, suggesting context-dependent regulatory roles in prokaryotes.
Area of Science:
- Genomics
- Molecular Biology
- Bioinformatics
Background:
- G-quadruplexes (G4s) are crucial regulatory DNA structures in eukaryotes.
- Their functions and prevalence in bacteria are largely unknown.
Purpose of the Study:
- To systematically analyze potential G-quadruplexes (PG4s) across a large bacterial genome dataset.
- To investigate the distribution, structural characteristics, and potential regulatory roles of G4s in bacteria.
Main Methods:
- Bioinformatic analysis of 1566 bacterial genomes to identify PG4s.
- Statistical comparisons with randomized genomes to assess non-random distribution.
- Ecological analysis correlating G4 density with host association and lifestyle.
Main Results:
- PG4s are non-randomly distributed in bacterial genomes, enriched in intergenic regions near gene start sites.
- Short-loop G4s, indicative of higher stability, are prevalent in these regulatory regions.
- G4 density is significantly lower in bacteria from stable, homothermic host environments compared to free-living species.
Conclusions:
- G-quadruplexes are conserved elements in bacterial genomes with potential roles in transcriptional regulation.
- G4 prevalence and function are context-dependent, influenced by environmental and host factors.
- These findings offer new insights into prokaryotic genome organization and regulation.
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