Warning: file_put_contents(/opt/frankenphp/design.onmedianet.com/storage/proxy/cache/7328ef060ad839667f025b2d3b1c895e.html): Failed to open stream: No space left on device in /opt/frankenphp/design.onmedianet.com/app/src/Arsae/CacheManager.php on line 36

Warning: http_response_code(): Cannot set response code - headers already sent (output started at /opt/frankenphp/design.onmedianet.com/app/src/Arsae/CacheManager.php:36) in /opt/frankenphp/design.onmedianet.com/app/src/Models/Response.php on line 17

Warning: Cannot modify header information - headers already sent by (output started at /opt/frankenphp/design.onmedianet.com/app/src/Arsae/CacheManager.php:36) in /opt/frankenphp/design.onmedianet.com/app/src/Models/Response.php on line 20
Viroids and the Origin of Life - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2021 Mar 28;22(7):3476.
doi: 10.3390/ijms22073476.

Viroids and the Origin of Life

Karin Moelling  1   2 , Felix Broecker  3
Affiliations
Review

Viroids and the Origin of Life

Karin Moelling et al. Int J Mol Sci. .

Abstract

Viroids are non-coding circular RNA molecules with rod-like or branched structures. They are often ribozymes, characterized by catalytic RNA. They can perform many basic functions of life and may have played a role in evolution since the beginning of life on Earth. They can cleave, join, replicate, and undergo Darwinian evolution. Furthermore, ribozymes are the essential elements for protein synthesis of cellular organisms as parts of ribosomes. Thus, they must have preceded DNA and proteins during evolution. Here, we discuss the current evidence for viroids or viroid-like RNAs as a likely origin of life on Earth. As such, they may also be considered as models for life on other planets or moons in the solar system as well as on exoplanets.

Keywords: RNase P; early earth; endosymbionts; exoplanets; meteorites; non-coding RNA; ribozymes.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Viroids/viroid-like RNAs/ribozymes early during evolution. The picture shows a viroid. Viroid/ribozymes and tRNAs can form spontaneously from a quasispecies of many RNA molecules, both exhibit enzymatic activities. The ribozyme RNase P processes pre-tRNA to the shorter tRNA, DNA can arise from RNA without a reverse transcriptase (RT), protein synthesis in ribosomes requires ribozymes as essential components (mRNA is messenger RNA, vRNA is viral RNA, PBS is the primer binding site for tRNA binding) (For details see text).
Figure 2
Figure 2
Multifunctionality of viroid-like RNA. Viroids/ribozymes and the ribozyme RNase P shown in the center, contribute to many phenomena, to diseases in plants such as palm trees, potatoes and avocado, to the human hepatitis delta virus, to protein synthesis in ribosomes, to regulatory circular RNAs, a chief-regulator, which regulates the levels of micro RNAs (miR), and to hammerhead ribozymes, symbolized as scissors, for gene therapy against cancer. Ribozymes can replicate in the test tube as shown in the model. The tRNA may be as ancient as the viroid and contributes to retrovirus replication. RT is the Reverse Transcriptase, which requires protein synthesis. The football symbolizes a retrovirus icosahedron. Carnations owe their pattern to a viroid and a para-retrovirus from plants (For details, see text) (RNA in red color).
See this image and copyright information in PMC

References

    1. Orgel L.E. Prebiotic chemistry and the origin of the RNA world. Crit. Rev. Biochem. Mol. Biol. 2004;39:99–123. doi: 10.1080/10409230490460765. - DOI - PubMed
    1. Flores R., Gago-Zachert S., Serra P., Sanjuán R., Elena S.F. Viroids: Survivors from the RNA world? Annu. Rev. Microbiol. 2014;68:395–414. doi: 10.1146/annurev-micro-091313-103416. - DOI - PubMed
    1. Wilson D.S., Szostak J.W. In vitro selection of functional nucleic acids. Annu. Rev. Biochem. 1999;68:611–647. doi: 10.1146/annurev.biochem.68.1.611. - DOI - PubMed
    1. Briones C., Stich M., Manrubia S.C. The dawn of the RNA World: Toward functional complexity through ligation of random RNA oligomers. RNA. 2009;15:743–749. doi: 10.1261/rna.1488609. - DOI - PMC - PubMed
    1. Lehman N. Origin of life: Cold-hearted RNA heats up life. Nat. Chem. 2013;5:987–989. doi: 10.1038/nchem.1811. - DOI - PubMed

LinkOut - more resources