The pursuit of understanding the origins of life (OoL) on and off Earth and the search for extraterrestrial life (ET) are central aspects of astrobiology.
Metabolism
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Metal Ions Turn On A Stereoselective Nonenzymatic Reduction Of Keto Acids By The Coenzyme NADH
Coenzymes are thought to have played a central role in the emergence of metabolism. However, studies in the context of prebiotic chemistry face the problem that outside of enzymes, many […]
Posted inBiochemistry & Organic Chemistry, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Status Report
A Novel Quinone Biosynthetic Pathway Illuminates The Evolution Of Aerobic Metabolism
The dominant organisms in modern oxic ecosystems rely on respiratory quinones with high redox potential (HPQs) for electron transport in aerobic respiration and photosynthesis.
![Rubisco form II structural differences between T. arctica UC1 and H. marinus. A) AlphaFold-generated [51,52] structures for H. marinus (transparent white) and T. arctica UC1 RbcII (dark blue) dimers aligned with ChimeraX [53]. Active sites colored red. Arrows point to the additional exposed active site residues in UC1 compared to H. marinus. The missing residues in UC1 at amino acid positions 78–82 (Fig. 4) are colored yellow on H. marinus structure (close44 up view in B). C) UC1 form II dimer with residue differences to H. marinus that confer a semi45 conservative or non-conservative change highlighted in orange.-- biorxiv.org](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/08/Prevalence-of-the-Calvin.png?resize=1200%2C720&ssl=1)
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Cryobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Icy Worlds, Microbiology & Virology, Status Report
Prevalence of the Calvin-Benson-Bassham Cycle in Chemolithoautotrophic Psychrophiles and the Potential for Cold-adapted Rubisco
The act of fixing inorganic carbon into the biosphere is largely facilitated by one enzyme, Rubisco. Beyond well-studied plants and cyanobacteria, many bacteria use Rubisco for chemolithoautotrophy in extreme environments […]
Posted inBiochemistry & Organic Chemistry, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report
Oxygen Metabolism In Descendants Of The Archaeal-Eukaryotic Ancestor
Asgard archaea were pivotal in the origin of complex cellular life. Hodarchaeales (Asgardarchaeota class Heimdallarchaeia) were recently shown to be the closest relatives of eukaryotes. However, limited sampling of these […]
Posted inBiochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Mars, Microbiology & Virology, Origin & Evolution of Life, Status Report
Siderite and Vivianite as Energy Sources for the Extreme Acidophilic Bacterium Acidithiobacillus Ferrooxidans in the Context of Mars Habitability
Past and present habitability of Mars have been intensely studied in the context of the search for signals of life. Despite the harsh conditions observed today on the planet, some […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Status Report
Ancient Nitrogenases Are ATP Dependent
Life depends on a conserved set of chemical energy currencies that are relics of early biochemistry. One of these is ATP, a molecule that, when paired with a divalent metal […]
Posted inBiochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Microbiology & Virology, Press Release, ROVs/Submersibles/Diving, Sample Return, Water/Hycean Worlds & Oceanography
Giant Deep-sea Vent Tubeworm Symbionts Use Two Carbon Fixation Pathways To Grow At Record Speeds
In the deep-sea environment of the East Pacific Rise, where sunlight does not penetrate and the surroundings are known for their extreme temperatures, skull-crushing pressures, and toxic compounds, lives Riftia […]
Posted inBiochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Multi-substrate Specificity Shaped The Complex Evolution Of The Aminotransferase Family Across The Tree Of Life
Aminotransferases (ATs) are an ancient enzyme family that play central roles in core nitrogen metabolism essential to all organisms. However, many of the AT enzyme functions remain poorly defined, limiting […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
GTP Before ATP: The Energy Currency At The Origin Of Genes
Life is an exergonic chemical reaction. Many individual reactions in metabolism entail slightly endergonic processes that are coupled to free energy release, typically as ATP hydrolysis, in order to go […]