Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"RNA world"”.
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Ribozymes of the RNA World: Investigating Ancient Enzymes through Modern Self-Cleaving Ribozymes.
Ribozymes are RNAs that can perform catalytic functions. The discovery of ribozymes was an important milestone in science because it not only opened new avenues of research but also provided insights into the origins of life on Earth. Early life most likely used RNA as catalysts for diverse …
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Evolution and Engineering of RNA-based Macromolecular Machines
The “RNA World Hypothesis” posits that extant life was likely preceded by a simpler primordial biology lacking DNA and proteins, relying instead on RNA for both heredity and catalysis. An essential component of an RNA world scenario would be an RNA “replicase” – a ribozyme capable of …
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Computational Techniques Applied to RNA Structures and Bacterial Genomes
… how complexity might arise in a prebiotic RNA World in which RNA polymerization through an RNA replicase was not possible. The experimental system exposes an initial 20-mer seed RNA to 180 min of continuous cycles of synthesis and degradation. The resulting pools of RNA were characterized …
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Nucleotide recognition and metal ion requirements of an RNA ligase ribozyme
… random sequence, catalyzes a reaction similar to RNA polymerization, positioning its 5'-nucleotide via a Watson-Crick base pair, forming a 3',5'-phosphodiester bond between its 5'-nucleotide and the substrate, and releasing pyrophosphate. The class I ligase forms the catalytic domain of an RNA …
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DESIGN OF HIGH-YIELDING NON-ENZYMATIC DNA AND RNA LIGATION SYSTEMS
… replication of nucleic acids, in particular RNA, will lend credence to the RNA world hypothesis which states that RNA was the first polymer on the prebiotic earth. One major challenge that currently still exists is how substrates can undergo ligation (i.e. form a covalent bond) in the absence …
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Evolution of Protein Structure
The aminoacyl-tRNA synthetases are one of the major protein components in the translation machinery. These essential proteins are found in all forms of life, and are responsible for charging their cognate tRNAs with the correct amino acid. The evolution of the tRNA synthetases is of fundamental …
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[RNA polymerase ribozymes]
The RNA World is a hypothetical ancient evolutionary era during which RNA was both genome and catalyst. During that time, RNA was the only kind of enzyme yet in existence, and one of its chief duties was the replication of RNA. This scenario presupposes that among all possible RNA sequences, there …
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Ice as a medium for RNA-catalysed RNA synthesis and evolution
… self-replication and evolution. According to the RNA World hypothesis, this could have been an RNA polymerase ribozyme capable of generating copies of itself from simple nucleotide precursors. In vitro evolution experiments have provided modern examples of such ribozymes, such as the R18 RNA …
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Establishing new approaches to unveil regulatory functions of tRNAs and their interactors
… study living systems. However, once the role of tRNAs was established in protein synthesis, the field moved on to other areas of the RNA world. With the mainstream application of systems-wide approaches, tRNAs have emerged as implicated in multiple regulatory networks beyond translation. These …
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The structural basis of RNA-catalyzed RNA polymerization
… chemically identical to a single turnover of RNA-dependent RNA polymerization. Such an activity would have been requisite for the emergence of a self-replicase ribozyme, an enzyme that, according to the RNA World hypothesis, would be fundamental for the emergence of life. Demonstrating the …
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Design and Characterisation of a Novel Artificial Life System Incorporating Hierarchical Selection
… system is presented, which is inspired by the RNA World hypothesis and is loosely based on Holland's Learning Classier Systems. The Molecular Classier System (MCS) takes a bottom-up, individual-based approach to building artificial bio-chemical networks. The MCS has been developed to …
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Prebiotic assembly and replication of nucleic acids
… for the origins of life, known as the "RNA world", relies on replication of ribonucleic acid (RNA) before the advent of protein enzymes and deoxyribonucleic acid (DNA). Essentially, the hypothesis relies on what some researchers believe is a parsimonious claim that RNA was the central …
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Potential prebiotic roles of (amino-)acylation in the synthesis and function of RNA
… ligation to give predominantly 3',5'-linked RNA that is acetylated at the ligation junction (acetyl-RNA). It was suggested that RNA emerged prebiotically via acetyl-RNA and also is proposed to have favourable genotypic properties due to greater propensity to form duplex structure. To study …
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In vitro evolution of ribozymes for self-synthesis
[Restricted]
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Genetic decoding dynamics: from its exploitation to enhance or rescue gene expression to a search for relevance for early evolution
… to these standard rules that are embedded in mRNA sequences. Elements in the mRNA can alter the meaning of specific codons or cause ribosomes to shift frame or with particular relevance to this thesis, result in ribosomes bypassing long untranslated regions. 30 – 50% of ribosomes successfully …
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Evolution and assembly of the ribosome
… bacterial ribosome consists of three ribosomal RNA (rRNA) molecules and approximately fifty ribosomal proteins (r-proteins), which are arranged into two subunits of unequal size and distinct function. The large subunit promotes formation of the peptide bond, and the small subunit enforces the …
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Critical phenomena in evolutionary dynamics
… of complexity in early biochemical systems. RNA biochemistry is characterized by large differences in synthetic yield, reactivity to polymerization, and degradation rate, and these properties are believed to result in pools of highly homogeneous, low complexity sequences. Using simulations of …