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 13 of 13 for “"the 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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Nucleotide recognition and metal ion requirements of an RNA ligase ribozyme
The class I ligase, a ribozyme previously isolated from 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 …
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DESIGN OF HIGH-YIELDING NON-ENZYMATIC DNA AND RNA LIGATION SYSTEMS
The demonstration of enzyme-free 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 …
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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
A critical event in the origin of life is thought to have been the emergence of a molecule capable of 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 …
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Establishing new approaches to unveil regulatory functions of tRNAs and their interactors
The discovery of the genetic code transformed the life sciences by providing an analytical framework to 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 …
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The structural basis of RNA-catalyzed RNA polymerization
The Class I ligase is an artificial ribozyme that catalyzes a reaction 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, …
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Design and Characterisation of a Novel Artificial Life System Incorporating Hierarchical Selection
In this thesis, a minimal artificial chemistry 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 …
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Prebiotic assembly and replication of nucleic acids
One of the most researched hypotheses 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 …
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Genetic decoding dynamics: from its exploitation to enhance or rescue gene expression to a search for relevance for early evolution
The genetic code and its readout were initially thought to be ‘frozen’ in the sense of being a fixed entity who’s decoding invariably involved standard rules. Recoding involves exceptions to these standard rules that are embedded in mRNA sequences. Elements in the mRNA can alter the meaning of …
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Evolution and assembly of the ribosome
The ribosome is a large macromolecular assembly responsible for protein synthesis in all living cells. A typical 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 …
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Critical phenomena in evolutionary dynamics
This thesis consists of five essays on evolutionary dynamics. In Chapters 1 and 2, we study the evolution of trust from the perspective of game theory. In the trust game, two players have a chance to win a sum of money. The "investor" begins with one monetary unit. She gives a fraction of that unit …