Solid-state nanogap systems are an emerging technology for in-situ life detection due to their single-molecule resolution of a wide range of biomolecules, including amino acids and informational polymers, at the […]
“Random DNA” is naturally active in the one-celled fungi yeast, while such DNA is turned off as its natural state in mammalian cells, despite their having a common ancestor a […]
Before life existed on Earth, there had to be chemistry to form organic molecules from the chemical elements nitrogen, sulphur, carbon and phosphorus.
Single-celled organisms, such as bacteria and archaea, have developed many ways to communicate with each other. For example, they might use tiny so-called extracellular vesicles (EVs) – membrane-enveloped packages smaller […]
![The proto-ribosome: (a) The symmetrical region within the 23S rRNA of E. coli ribosome (PDB code 2AW4). The A- and P-subregions, in blue and green, respectively, throughout. Helices H68-H71 were removed to reveal the PTC area. (b) 2D scheme of the symmetrical region (on colored background), drawn in a manner exhibiting the twofold symmetry, with the central loop of domain V (C-loop) at its center. The sequence assigned to the remnant of the DPR (boundary marked) is composed of two L-shaped molecules, the A- and P-DPR monomers. Nucleotides conserved by more than 97% in each of the three life domains, as detected in the CRW site [77], are presented by capital letters and the remaining nucleotides by circles. (c) Overlap of the DPR fold as found in the high-resolution structures of archaea (PDB code 1VQ6), bacteria (PDB code 2WDL), and eukarya (PDB code 3U5D) ribosomes, portraying its extreme tertiary conservation in the three life domains. The pocket is projected approximately along the symmetry axis, with the reactants (PDB code 2WDL) positioned at the bottom of the cavity. (d) Overlap of the A- and P-DPR monomers from E. coli (PDB code 2AW4), obtained by rotating one monomer by 179.6° around the symmetry axis. The projection direction is perpendicular to the one shown in (c). tRNA molecule (PDB code 4TRA, in gray) is overlaid with its anticodon arm overlapping H89 and H93 helices from the P- and A-monomers, respectively. Magnified nucleotides from the superimposed stems of H89 and its symmetry-related H93 depict the conformational match. Nucleotide A2602, which is functionally active, bulges into the PTC and breaks the overall symmetry. (e) Model of a minimal coded proto-ribosome assembled from four L-shaped entities of about 60–70 nucleotides each (derived from PDB code 1VY4), i.e., the A-, P-DPR monomers, the proto-SSU (purple), and the bridging element (dark red), complexed with mRNA (orange) and tRNA (cyan). -- LIFE](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/02/Three-Biopolymers.png?resize=1200%2C716&ssl=1)
To track down the possible roots of life, various models for the initial living system composed of different combinations of the three extant biopolymers, RNA, DNA, and proteins, are presented.
A chemical compound essential to all living things has been synthesised in a lab in conditions that could have occurred on early Earth, suggesting it played a role at the […]
JAXA (Japan Aerospace Exploration Agency) astronaut and Expedition 70 Flight Engineer Satoshi Furukawa works in the Kibo laboratory module’s Life Science Glovebox extracting DNA samples for the new uTitan investigation.
Molecular assembly can be designed by fusing binding domains. A precise optimization of the level of compaction of the assembly using linker of different lengths or compositions can provide a […]
Long-term space exploration exposes humans to radiation that can damage deoxyribonucleic acid or DNA, which carries the genetic information for our development and functioning. Conditions in space also affect the […]
![AlphaFold structures of NLS-containing proteins. AlphaFold2 structures modeled from NLS-predicted proteins that had no SwissProt BLASTP hits (E-value < 1e-15). [AB] Structures for those that had a FoldSeek hit against the AlphaFold2 SwissProt database (E-value < 1E-05). The yellow and blue structures indicate the reference and the predicted H. exemplaris protein structures, respectively. [A] BV898_05254.p01 (5-hydroxytryptamine receptor 1E (AF-Q6VB83-F1-model_v4.pdb E-value = 6.22E-12, RMSD between 163 pruned atom pairs is 1.124 angstroms across all 353 pairs: 10.861) [B] Ecdysone-induced protein 78C (AF-P45447-F1-model_v4 E26 value 4.48E-08, RMSD between 84 pruned atom pairs is 1.044 angstroms; across all 391 pairs: 32.283) [C-F] Transcripts that had an IUPRED3 score of 1.0 [C] BV898_03773.p01, [D] BV898_07132.p01 [E] BV898_12866.p01 [F] BV898_18010.p01. -- biorxiv.org](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/02/Transcriptome-analysis-1.png?resize=1200%2C717&ssl=1)
Tardigrades are microscopic animals that are renowned for their capabilities of tolerating near-complete desiccation by entering an ametabolic state called anhydrobiosis.
