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bioRxiv · 10.64898/2026.07.27.740603

Two Novel Rod-Like Circular RNAs from the Oroarctic Tundra Soil Display Candidate Ribozyme-Like Features: An In Silico Characterization

Williams, N.·Wolfram, G.·Zhang, A.·Tessler, M. E.·Jung, G.
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Abstract

The recent discovery of obelisks, novel deltaviruses, and other viroid-like circular RNAs has greatly expanded the known diversity of autonomous RNA elements. However, cold terrestrial ecosystems remain comparatively undersampled for these molecules. Using a structure-based modification of the Tormentor pipeline, we assembled two putative non-coding rod-like circular RNAs from winter metatranscriptomes of oroarctic tundra soil collected near Kilpisjarvi, Finland. Sequence-based searches identified no meaningful homologs for either RNA. Structure-based analyses identified affinities to deltavirus-like ribozymes in Rod 1 and to hammerhead ribozymes in Rod 2, with structural compatibility confirmed by integration into an established covariation model. Rod 1 was additionally detected in independent alpine metatranscriptomic datasets, whereas Rod 2 was not identified beyond the original sample. Collectively, these results identify Rod 1 as a strong candidate viroid-like RNA bearing a putative ribozyme-like structure motif that warrants experimental validation, while Rod 1 remains a preliminary candidate requiring further confirmation.

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Williams, N., Wolfram, G., Zhang, A., Tessler, M. E., Jung, G.. 2026-07-27. Two Novel Rod-Like Circular RNAs from the Oroarctic Tundra Soil Display Candidate Ribozyme-Like Features: An In Silico Characterization. https://doi.org/10.64898/2026.07.27.740603

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