Evidence map›Paper›PMID 42010269›Full record

ArticleNature communications2026

Identification of hot spring Obelisk-like RNA replicons and expanded diversity of the Obelisk superfamily.

Syun-Ichi Urayama, Akihito Fukudome, Pascal Mutz, Yosuke Matsushita, Yoshihiro Takaki, Yosuke Nishimura, Sofia Medvedeva, Mart Krupovic, Eugene V Koonin, Takuro Nunoura

Abstract read
In one paragraph

Article in Nature communications, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
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

10 authors.

Syun-Ichi UrayamaLaboratory of Biology for Extreme Molecule, Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan. urayama.shunichi.gn@u.tsukuba.ac.jp.ORCID 0000-0001-5318-9212
Akihito Fukudome *Department of Biology and Department of Molecular and Cellular Biochemistry, Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA.ORCID 0000-0001-8924-1035
Pascal Mutz *Computational Biology Branch, Division of Intramural Research, National Library of Medicine, Bethesda, MD, USA.ORCID 0000-0002-0430-2095
Yosuke MatsushitaInstitute for Plant Protection, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan.ORCID 0000-0002-1325-3125
Yoshihiro TakakiSuper-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine Science and Technology (JAMSTEC), Yokosuka, Japan.ORCID 0000-0002-1247-4946
Yosuke NishimuraSuper-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine Science and Technology (JAMSTEC), Yokosuka, Japan.ORCID 0000-0002-8028-3228
Sofia MedvedevaCell Biology and Virology of Archaea Unit, Institut Pasteur, CNRS UMR6047, Université Paris Cité, Paris, France.ORCID 0000-0002-7841-0814
Mart KrupovicCell Biology and Virology of Archaea Unit, Institut Pasteur, CNRS UMR6047, Université Paris Cité, Paris, France.ORCID 0000-0001-5486-0098
Eugene V KooninComputational Biology Branch, Division of Intramural Research, National Library of Medicine, Bethesda, MD, USA.ORCID 0000-0003-3943-8299
Takuro NunouraResearch Center for Bioscience and Nanoscience (CeBN), JAMSTEC, Yokosuka, Japan.ORCID 0000-0003-2323-0880

Funding

Ministry of Education, Culture, Sports, Science and Technology (MEXT) 20K20377Ministry of Education, Culture, Sports, Science and Technology (MEXT) 23K18146Ministry of Education, Culture, Sports, Science and Technology (MEXT) 24K02083Ministry of Education, Culture, Sports, Science and Technology (MEXT) 25K22486Ministry of Education, Culture, Sports, Science and Technology (MEXT) JPMJFR240T
6 · The paper itself

Abstract

Recent extensive metatranscriptome mining vastly expanded the range of apparently covalently closed circular (ccc) RNA replicons. A notable family of such replicons is Obelisks, ~1 kilobase (kb) cccRNAs encoding a protein with a unique fold, Oblin-1, and detected in diverse metatranscriptomes. To identify potential cccRNAs in a sequence similarity-independent manner, we adopt the Fragmented and primer-Ligated DsRNA Sequencing (FLDS) method to selectively sequence double-stranded (ds) RNAs, replicative intermediates of RNA replicons. We focus on candidates with predicted extensive intramolecular base-pairing, a hallmark of viroid-like elements. Using FLDS, we explore metatranscriptomes from acidic hot springs in Japan and discover a distinct family of Obelisks apparently associated with thermoacidophilic bacteria (Hot spring Obelisks, HsObs). Despite lacking sequence similarity to known Oblins, HsObs share key features, including ~1 kb genome size, rod-like RNA secondary structure, and the predicted fold of the encoded protein, HsOblin. A comprehensive metatranscriptome search for Oblin-1 and HsOblin homologs expands Obelisk diversity about two-fold, revealing multiple subfamilies sharing the same core fold,. some of which are also predicted to encode additional small proteins with simple alpha-helical folds. These findings highlight Obelisks as widespread and overlooked components of microbial ecosystems, expanding understanding of viroid-like RNA replicon diversity and evolution.

Indexed as

BacteriaHot SpringsRepliconRNABase SequenceMolecular Sequence DataNucleic Acid ConformationPhylogenyRNA, Double-StrandedRNARNA, Double-Stranded

Identifiers

PMID42010269
PMCPMC13096302

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

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 Socratic graph.