ribozyme Archives

Structure Of An RNA polymerase Ribozyme Replication Complex

by Keith CowingSeptember 10, 2026September 10, 2026

[biorxiv.org] Life began with the emergence of a molecule that could replicate its own genetic material, a task plausibly mediated by an RNA-dependent RNA polymerase ribozyme.

An RNA library containing a partially randomized sequence having an estimated complexity of ~1014 sequences

Origin & Evolution of Life

How Early RNA-based Life May Have Repaired Its Genome

by Keith CowingJuly 14, 2026July 14, 2026

[University of Notre Dame] In most modern cells, DNA stores the genetic blueprint, and relies on proteins to replicate, repair and build from those blueprints. At the same time, proteins […]

Schematic of the selection step in the doped in emulsio selection.

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release

What Powered the Earth’s Earliest Life?

by Keith CowingJune 12, 2026June 12, 2026

Early biological systems likely relied on RNA molecules to copy themselves and drive simple chemical reactions.

A simplified illustration of the model. It depicts a cross-section of a spherical phospholipid vesicle, highlighting its membrane with hydrophilic heads and hydrophobic tails. Racemic d- and l-ribose (green) can both penetrate the membrane and capture the PO groups, but d-ribose undergoes this process more quickly and is preferentially trapped (purple) inside the vesicle. --Life

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Status Report

Stereoselective Phosphorylation of d-Ribose as a Driver of Life’s Homochirality

by Keith CowingJune 1, 2026June 1, 2026

Life demonstrates remarkable homochirality of its major building blocks: nucleic acids, amino acids, sugars, and phospholipids. Phospholipid bilayer vesicles (liposomes) are formed at the water/air interface from Langmuir layers and […]

Evidence for ribozyme mass extinction. (A) Abundance distribution across all ten known small self-cleaving ribozyme families, showing the hammerhead's 91% dominance, a pattern characteristic of disaster taxa following mass extinction events. (B) Circular phylogeny of 80,548 unique hammerhead sequences colored by host taxonomic group. The star-like topology is consistent with post-bottleneck radiation, and the interspersion of distantly related host phyla around the tree reflects repeated independent colonization events rather than co-speciation, consistent with horizontal transfer of a single dominant survivor lineage. (C) Null distribution tests for Tajima's D (left) and Fu's Fs (right), each based on 10,000 coalescent replicates (n = 200, S = 40). Blue and orange histograms show the null distributions under neutral expectations; red dashed lines indicate the observed values (D = +2.28, upper-tail p = 0.013; Fs = −618.0, p < 0.0001). Observed D falls in the extreme upper tail (98.7% of null replicates below observed), indicating deep hierarchical structure; observed Fs falls far below any null replicate, indicating massive haplotype excess. The discordance between positive D and extremely negative Fs is diagnostic of ancient divergence preserved through a bottleneck followed by rapid within-lineage expansion. Full-sample values (n = 5,036) are D = +3.79, Fs = −690.8. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

A Ribozyme Mass Extinction At The RNA-cellular Boundary And Its Potential Imprint On The Genetic Code

by Keith CowingApril 13, 2026April 13, 2026

The transition from the RNA world to cellular life remains one of the least understood events in the history of biology.

Ribozymes are relics of molecular life forms

Biochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report

Modularity, Ecology, And Theoretical Evolution Of The Ribozyme Body Plan

by Keith CowingMarch 12, 2026March 12, 2026

Ribozymes are relics of molecular life forms from the primitive earth that are embedded within modern genomes across all kingdoms of life. Despite significant knowledge from decades of bioinformatic and […]

Predicted secondary structure of QT45 ribozyme with nucleotide color corresponding to fitness for each of the three possible single mutations at each position, displayed in the same order as the three representative mutations shown and colored as in Fig. 2E. Base pair annotations are provided, where the upper rectangle connecting two bases shows the average fitness or epistasis of measured base pair-breaking double mutations. For canonical base pairs, the inner small rectangles show (from left to right) the fitness or epistasis of mutations to base pairs UG, UA, GC, CG, AU, GU. For the non-canonical base pair C11-U35, the base pairs shown are UG, UA, GC, UC, CU, CG, AU, GU. (A) Base pair annotations are colored according to fitness. Base pair-retaining mutations generally have higher fitness than base pair-breaking mutations. (B) Base pair annotations are colored according to epistasis. Base pair-retaining mutations generally show more positive epistasis compared to base pair-breaking mutations. -- Science

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

A Small Polymerase Ribozyme That Can Synthesize Itself And Its Complementary Strand

by Keith CowingFebruary 16, 2026February 16, 2026

The emergence of a chemical system capable of self-replication and evolution is a critical event in the origin of life.

Selection protocol used to isolate ligase ribozymes.

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

Emergence Of Diverse Ligase Reactivities From A Single RNA Evolution Experiment

by Keith CowingJanuary 23, 2026January 23, 2026

RNA-catalyzed assembly of RNA strands was one of the most essential enzymatic functions in a primordial RNA-based biology.

Artistic depiction of liposome formation and evolution. Liposomes formed on the surface of the Archean water pools are destroyed by Solar UV unless they acquire two adaptive traits – the heavy content that sinks the liposomes to the bottom of the pool and facilitates protection from UV, and the formation of resilient autocatalytic membrane composition that ensures liposomal survival, fusion, fission, and mutation of the components, thus providing liposomes adaptation and persistence. -- q-bio.PE

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Microbiology & Virology, Origin & Evolution of Life, Status Report

Heuristic Model On The Origin Of The Homochirality Of Life

by Keith CowingJanuary 2, 2026January 3, 2026

Life demonstrates remarkable homochirality of its major building blocks: nucleic acids, amino acids, sugars, and phospholipids. We propose a mechanism that places the root of life homochirality in the formation […]

Liquid brine veins, where RNA molecules can replicate, surround solid ice crystals in water ice, as seen with an electron microscope. Credit Philipp Holliger, MRC LMB

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release

Chemists Recreate How RNA Might Have Reproduced For The First Time

by Keith CowingMay 29, 2025May 28, 2025

Chemists at UCL and the MRC Laboratory of Molecular Biology have demonstrated how RNA (ribonucleic acid) might have replicated itself on early Earth – a key process in the origin […]