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 […]
RNA world
![Kinetic processes of the strand-based RNA reactor model [12,13,15] and their projection onto motif kinetics. We consider heteropolymer strands consisting of the two complementary nucleotides X and Y, which could represent RNA or DNA nucleotides. (a) Schematic of the reactions within the strand reactor, including hybridization, dehybridization, templated ligation, and cleavage of oligonucleotide strands. Strands that are not covalently linked are separated by small gaps; four-nucleotide motifs, including 3′ or 5′ ends, are highlighted in green. In templated ligation, a 3′- and a 5′-end motif build a six-nucleotide motif that contains three overlapping four-nucleotide motifs. (b) At the level of sequence motifs, the kinetics are based on motif production and motif breakage reactions. In four-nucleotide motifs, strand ends are marked with 3′ or 5′, respectively. Templated ligation generates longer strands containing additional motifs, thereby contributing to motif production, while strand cleavage leads to to motif breakage. Hybridization is not explicitly represented in the motif-level description; instead, it is implicitly incorporated into the rate constants for motif production and breakage by assuming a hybridization-dehybridization equilibrium and deducing the corresponding dissociation constants. -- Physical Review E](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/03/Sequence-Motif-Dynamics.png?resize=1200%2C720&ssl=1)
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Sequence Motif Dynamics In RNA Pools
In RNA world scenarios, pools of RNA oligomers form strongly interacting, dynamic systems, which enable molecular evolution.
Posted inBiochemistry & Organic Chemistry, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Origins Of Life: Chemistry And Evolution
Direct chemical synthesis and chemical evolution are conceptually different models for the prebiotic origin of RNA and other biopolymers. These models generate distinct predictions and motivate different experimental approaches.
Posted inBiochemistry & Organic Chemistry, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Emergence Of Diverse Ligase Reactivities From A Single RNA Evolution Experiment
RNA-catalyzed assembly of RNA strands was one of the most essential enzymatic functions in a primordial RNA-based biology.
![Scheme of a geothermal valley between two snow-covered Hadean volcanoes. The fumaroles, thermal springs, apron pools, and terracettes are shown based on the reconstruction of the 3.48 Ga old Hadean geothermal system. On the right, various reactions of CO2 sequestration in a Hadean volcanic system are indicated, see Section 3.2.5 and Section 3.2.6. Inserts: (A) volcanic fumaroles, image from https://home.nps.gov/articles/000/fumaroles.htm, credit: USGS. (B) Schematic cross section of a pH-neutral hot spring, redrawn with modifications from [341,342]. (C) White Terraces of New Zealand as an example of volcanic terracettes (painted by Charles Bloomfield in 1884, two years before the terraces were buried under the waters of the lake Rotomahana following the eruption of Mt. Tarawera. Image credit: Museum of New Zeeland, https://collections.tepapa.govt.nz/object/42254, accessed on 23 December 2024.). (D) Interconversion of nitriles, amides, and ammonium salts of organic acids, represented by their simplest species, in geothermal pools in the presence of inorganic catalysts; each of the nitrogen-containing compounds shown is considered as a substrate for further synthetic reactions. Formamide and other amides, as the least volatile components, may have sustained/buffered the whole system. -- Life via PubMed](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/07/Origin-Of-The-RNA-World-In.png?resize=1200%2C720&ssl=1)
Posted inAstrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Extinction events, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Impact events, Moon, Origin & Evolution of Life, Status Report
Origin Of The RNA World In Cold Hadean Geothermal Fields Enriched In Zinc And Potassium – Abiogenesis As A Positive Fallout From The Moon-Forming Impact?
The ubiquitous, evolutionarily oldest RNAs and proteins exclusively use rather rare zinc as transition metal cofactor and potassium as alkali metal cofactor, which implies their abundance in the habitats of […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
An RNA Condensate Model For The Origin Of Life
The RNA World hypothesis predicts that self-replicating RNAs evolved before DNA genomes and coded proteins. Despite widespread support for the RNA World, self-replicating RNAs have yet to be identified in […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Protocell Effects on RNA Folding, Function, and Evolution
Creating a living system from nonliving matter is a great challenge in chemistry and biophysics. The early history of life can provide inspiration from the idea of the prebiotic “RNA […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
The RNA World With Inhibitors
During the evolution of the RNA World, compartments, which were fragments of space surrounded by a primitive lipid membrane, had to have emerged.
Posted inAstrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Genomics, Proteomics, Bioinformatics, Imaging & Spectroscopy, Interstellar, Meteorites & Asteroids, Origin & Evolution of Life, Press Release
Astrochemistry: The Mystery of Life’s Handedness Deepens
The mystery of why life uses molecules with specific orientations has deepened with a NASA-funded discovery that RNA — a key molecule thought to have potentially held the instructions for […]
Posted inAstrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Protocell Effects on RNA Folding, Function, and Evolution
Creating a living system from nonliving matter is a great challenge in chemistry and biophysics. The early history of life can provide inspiration from the idea of the prebiotic “RNA […]