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Updated: Oct 18, 2025

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
G-quadruplexes in genomes of viruses infecting eukaryotes or prokaryotes are under different selection pressures from
Zhen Li1, Sheng Hu Qian2, Fan Wang3
1State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China; Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan 430070, China; College of Science, Huazhong Agricultural University, Wuhan 430070, China.
Abstract:
G-quadruplexes in viral genomes can be applied as the targets of antiviral therapies, which has attracted wide interest. However, it is still not clear whether the pervasive number of such elements in the viral world is the result of natural selection for functionality. In this study, we identified putative quadruplex-forming sequences (PQSs) across the known viral genomes and analyzed the abundance, structural stability, and conservation of viral PQSs. A Viral Putative G-quadruplex Database (http://jsjds.hzau.edu.cn/MBPC/ViPGD/index.php/home/index) was constructed to collect the details of each viral PQS, which provides guidance for selecting the desirable PQS. The PQS with two putative G-tetrads (G2-PQS) was significantly enriched in both eukaryotic viruses and prokaryotic viruses, whereas the PQSs with three putative G-tetrads (G3-PQS) were only enriched in eukaryotic viruses and depleted in prokaryotic viruses. The structural stability of PQSs in prokaryotic viruses was significantly lower than that in eukaryotic viruses. Conservation analysis showed that the G2-PQS, instead of G3-PQS, was highly conserved within the genus. This suggested that the G2-quadruplex might play an important role in viral biology, and the difference in the occurrence of G-quadruplex between eukaryotic viruses and prokaryotic viruses may result from the different selection pressures from hosts.
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