Evidence map›Paper›PMID 42258535›Full record

ArticleNucleic acids research2026

Topoisomerase III limits RecA-dependent DNA amplification in the chromosome terminus with RecG.

Ali Dadras, Armelle Le Campion, Marc Drolet

Abstract read
In one paragraph

Article in Nucleic acids research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Ali DadrasDépartement de microbiologie, infectiologie et immunologie, Faculté de médecine, Université de Montréal, Montréal, P. Québec H3C 3J7, Canada.
Armelle Le CampionInstitut Courtois d'innovation biomédicale, Faculté de médecine, Université de Montréal, Montréal, P. Québec H3C 3J7, Canada.
Marc DroletDépartement de microbiologie, infectiologie et immunologie, Faculté de médecine, Université de Montréal, Montréal, P. Québec H3C 3J7, Canada.ORCID 0000-0001-7457-0821

Funding

Fonds de Recherche du QuébecNational Sciences and Engineering Research Council of Canada RGPIN-2022-03760Université de Montréal
6 · The paper itself

Abstract

Topoisomerase (topo) III is a ubiquitous type IA enzyme whose role in suppressing inappropriate recombination is well established in eukaryotes but remains poorly defined in prokaryotes. In Escherichia coli, deletion of topB (encoding topo III) in topA mutants (topo I, which normally prevents R-loop formation) leads to pronounced Ter/Tus barrier-dependent DNA amplification in the chromosomal terminus region. In recG mutants, this phenotype was recently attributed to RecA-mediated D-loop formation at DNA double-strand ends (DSEs) generated at Ter/Tus barriers, triggering replication restart in the incorrect orientation (re-replication). Here, our data indicate that, as in recG mutants, RecA drives repeated cycles of Ter/Tus barrier-dependent DSE formation and re-replication, thereby promoting chromosomal terminus DNA amplification in topA topB cells. Deletion of topB enhances Ter/Tus-dependent amplification in rnhA cells but not in recG cells. Moreover, deletion of recG or topB, but not recQ, markedly exacerbates the replication-completion defect of topA mutants, unless recA is deleted or topo IV is overproduced. Together, these findings suggest that topo III and RecG cooperate to restrain RecA-mediated re-replication at sites of DSE formation, thereby preventing pathological DNA amplification.

Indexed as

Chromosomes, BacterialDNA, BacterialDNA ReplicationDNA Topoisomerases, Type IEscherichia coli ProteinsRec A RecombinasesDNA-Binding ProteinsEscherichia coliDNA, BacterialDNA-Binding ProteinsDNA Topoisomerases, Type IEscherichia coli ProteinsrecA protein, E coliRec A RecombinasesRecG protein, E colitopA protein, E coli

Identifiers

PMID42258535
PMCPMC13244152

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.