Discoveries

Transition Metals Enhance Prebiotic Depsipeptide Oligomerization Reactions Involving Histidine


The authors tested the effect of Zn2+ and other metal ions on polymerization of histidine (His) and glycolic acid into depsipeptides in dry-down reactions. The results here show that interactions of depsipeptides with metal ions could have influenced early chemical evolution of proto-peptides. Data showed that addition of Zn2+ increased the average lengths of His-

Read more

Water and Life: The Medium is the Message


Water is the medium of life and a key compound produced and/or consumed during organic and inorganic catabolism and anabolism of molecules. Water comprises 99.4% of metabolites in Escherichia coli and serves as a recurring reaction substrate, intermediate, cofactor, and product. The authors calculated a lower limit for extent of participation of water molecules in chemical

Read more

Amino Acid Specific Nonenzymatic Montmorillonite-Promoted RNA Polymerization


The authors examined the effects of different amino acids on activated nucleotide, 2-MelmpA, montmorillonite-promoted polymerization at neutral pH. Polymerization in the presence of non-polar and acidic amino acids resulted in longer oligomer formation of up to 10 mers compared to the reference system, which does not contain amino acids, indicating facilitation of polymerization of 2-MelmPA.

Read more

Expansion Segments in Bacterial and Archaeal 5S Ribosomal RNAs


5S rRNA is an essential part of the central protuberance in the large ribosomal subunit. Although its exact function is not known, it is believed to be involved in intraribosomal interactions, which impose evolutionary constraints that make this small RNA one of the most conserved ribosomal components among all three domains of life. Thus, examining structural abnormalities such as expansion

Read more

Human Ribosomal G-quadruplexes Regulate Heme Bioavailability


Heme is an essential signaling molecule in cells, but it must be tightly regulated due to its potential toxicity. Although the proteins that synthesize and degrade heme have been extensively studied, the regulation of heme bioavailability is currently poorly understood. The authors demonstrate that human rRNA tentacles form G-quadruplexes (G4s) in vivo that regulate cellular heme

Read more

Rapid deployment of smartphone-based augmented reality tools for field and online education in structural biology


3D structure visualization via augmented reality (AR) is practical for education purposes, especially remote instruction. Other molecular visualization software have limitations such as ease of instructor implementation and availability of student hardware. Augment is an AR application that can be easily utilized by instructors and operated by students on their smartphones. US smartphone

Read more

Further Characterization of the Pseudo-Symmetrical Ribosomal Region


Peptide bond synthesis occurs in the peptidyl transferase center (PTC) of the large ribosomal subunit (LSU). There is an area of twofold pseudo-symmetry (SymR) in and around the PTC comprised of about 178 nucleotides. It has two halves, one half associated with the ribosomal A site, and the other with the P site. SymR is theorized to have emerged by an heterodimerization event in the prebiotic

Read more

Characterization of SymR and Cryo-EM of Halococcus morrhuae 5S rRNA Insertion


Two papers focusing on the ribosomes were recently published. The first paper highlights the discovery of an area of twofold pseudosymmetry (SymR) within the peptidyl transferase center of the modern ribosome (Rivas and Fox 2020). This observation strongly suggests that the very core of the ribosome arose from a dimerization event between two modest-sized RNAs. It was previously shown that at

Read more

Supersized ribosomal RNA expansion segments in Asgard archaea


The ribosome is comprised of ribosomal RNA (rRNA) and ribosomal proteins (rProteins). The ribosomal common core includes the structurally conserved rRNA and rProtein of all species. The common core connects all life back to the Last Universal Common Ancestor (LUCA). In eukaryotes, the common core rRNA is elaborated with expansion segments (ESs), making the eukaryotic rRNA longer and more

Read more

Cutting In-line with Iron: Ribosomal Function and Non-oxidative RNA Cleavage


Ribosomes originated long before the Great Oxidation Event (GOE) and their structure and function are strongly dependent on divalent metals (M2+). Thus, understanding ribosomal evolution requires characterization of ribosomal interactions with M2+ ions under pre-GOE conditions: in the presence of abundant Fe2+ and in the absence of O2. Here, we have

Read more

Pages