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A Non-Canonical Nucleotide from Viral Genomes Interferes with the Oxidative DNA Damage Repair System Full article

Journal DNA repair
ISSN: 1568-7856
Output data Year: 2024, Volume: 133, Article number : 103605, Pages count : 8 DOI: 10.1016/j.dnarep.2023.103605
Tags DNA damage; DNA repair; 8-oxoguanine; 2,6-diaminopurine; DNA polymerases; DNA glycosylases; Non-canonical genomes
Authors Yudkina Anna V. 1,2 , Endutkin Anton V. 1 , Diatlova Evgeniia A. 1 , Zharkov Dmitry O. 1,2
Affiliations
1 SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russia
2 Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia

Abstract: Oxidative damage is a major source of genomic instability in all organisms with the aerobic metabolism. 8-Oxoguanine (8-oxoG), an abundant oxidized purine, is mutagenic and must be controlled by a dedicated DNA repair system (GO system) that prevents G:C→T:A transversions through an easily formed 8-oxoG:A mispair. In some forms, the GO system is present in nearly all cellular organisms. However, recent studies uncovered many instances of viruses possessing non-canonical nucleotides in their genomes. The features of genome damage and maintenance in such cases of alternative genetic chemistry remain barely explored. In particular, 2,6-diaminopurine (Z nucleotide) completely substitutes for A in the genomes of some bacteriophages, which have evolved pathways for dZTP synthesis and specialized polymerases that prefer dZTP over dATP. Here we address the ability of the GO system enzymes to cope with oxidative DNA damage in the presence of Z in DNA. DNA polymerases of two different structural families (Klenow fragment and RB69 polymerase) were able to incorporate dZMP opposite to 8-oxoG in the template, as well as 8-oxodGMP opposite to Z in the template. Fpg, a 8-oxoguanine–DNA glycosylase that discriminates against 8-oxoG:A mispairs, also did not remove 8-oxoG from 8-oxoG:Z mispairs. However, MutY, a DNA glycosylase that excises A from pairs with 8-oxoG, had a significantly lower activity on Z:8-oxoG mispairs. Similar preferences were observed for Fpg and MutY from different bacterial species (Escherichia coli, Staphylococcus aureus and Lactococcus lactis). Overall, the relaxed control of 8-oxoG in the presence of the Z nucleotide may be a source of additional mutagenesis in the genomes of bacteriophages or bacteria that have survived the viral invasion.
Cite: Yudkina A.V. , Endutkin A.V. , Diatlova E.A. , Zharkov D.O.
A Non-Canonical Nucleotide from Viral Genomes Interferes with the Oxidative DNA Damage Repair System
DNA repair. 2024. V.133. 103605 :1-8. DOI: 10.1016/j.dnarep.2023.103605 WOS Scopus ANCAN PMID OpenAlex
Dates:
Submitted: Jul 8, 2023
Accepted: Nov 15, 2023
Published online: Nov 20, 2023
Published print: Jan 1, 2024
Identifiers:
Web of science: WOS:001166231400001
Scopus: 2-s2.0-85178554216
Chemical Abstracts: 2023:2491871
Chemical Abstracts (print): 185:108434
PMID: 38042029
OpenAlex: W4388818892
Citing:
DB Citing
OpenAlex 1
Web of science 1
Scopus 1
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