Emergence Of Translation Research Articles

Evolution of the RNA world: From signals to codes

The accumulated material in evolutionary biology, greatly enhanced by the achievements of modern synthetic biology, allows us to envision certain key hypothetical stages of prebiotic (chemical) evolution. This is often understood as the further evolution in the RNA World towards the RNA-protein World. It is a path towards the emergence of translation and the genetic code (I), signaling pathways with signaling molecules (II), and the appearance of RNA-based components of future gene regulatory networks (III). We believe that these evolutionary paths can be constructively viewed from the perspective of the concept of biological codes (Barbieri, 2003). Crucial evolutionary events in these directions would involve the emergence of RNA-based adaptors. Such adaptors connect two families of functionally and chemically distinct molecules into one functional entity.The emergence of primitive translation processes is undoubtedly the major milestone in the evolutionary path towards modern life. The key aspect here is the appearance of adaptors between amino acids and their cognate triplet codons. The initial steps are believed to involve the emergence of proto-transfer RNAs capable of self-aminoacylation.The second significant evolutionary breakthrough is the development of biochemical regulatory networks based on signaling molecules of the RNA World (ribonucleotides and their derivatives), as well as receptors and effectors (riboswitches) for these messengers. Some authors refer to this as the “lost language of the RNA World."The third evolutionary step is the emergence of signal sequences for ribozymes on the molecules of their RNA targets. This level of regulation in the RNA World is comparable to the gene regulatory networks of modern organisms. We believe that the signal sequences on target molecules have been rediscovered and developed by evolution into the gene regulatory networks of modern cells.In conclusion, the immense diversity of modern biological codes, in some of its key characteristics, can be traced back to the achievements of prebiotic evolution.

Informatic Capabilities of Translation and Its Implications for the Origins of Life.

The ability to encode and convert heritable information into molecular function is a defining feature of life as we know it. The conversion of information into molecular function is performed by the translation process, in which triplets of nucleotides in a nucleic acid polymer (mRNA) encode specific amino acids in a protein polymer that folds into a three-dimensional structure. The folded protein then performs one or more molecular activities, often as one part of a complex and coordinated physiological network. Prebiotic systems, lacking the ability to explicitly translate information between genotype and phenotype, would have depended upon either chemosynthetic pathways to generate its components-constraining its complexity and evolvability- or on the ambivalence of RNA as both carrier of information and of catalytic functions-a possibility which is still supported by a very limited set of catalytic RNAs. Thus, the emergence of translation during early evolutionary history may have allowed life to unmoor from the setting of its origin.The originof translation machineryalso represents an entirely novel and distinct threshold of behavior for which there is no abiotic counterpart-it could be the only known example of computing that emerged naturally at the chemical level. Here we describetranslation machinery's decoding system asthe basis of cellular translation's information-processing capabilities, and the four operation types that find parallels in computer systems engineering that this biological machineryexhibits.

Causation and Forms of Relationships of the Georgian Literature with the Literatures of the Slavic Region (on the material of the Polish-Georgian and Georgian-Bulgarian literary relations)

The paper provides a brief overview of literary contacts between Georgia, Poland and Bulgaria from the time of their inception to the present day. Literary connections between peoples are due to the similarity of historical conditions in which they developed over a long period of time: Bulgaria from the end of the 14th to the end of the 19th century was under the rule of the Ottoman Empire, Georgia and Poland since the end of the 18th century were part of the Russian Empire. The desire to regain their lost independence and the growing national liberation movement brought together the peoples of Georgia, Poland and Bulgaria, which was reflected in their cultural relations. One of the main forms of literary connections is translation, which reflects the direct contact, communication of different national literatures. The emergence of translation is closely connected with the needs of society, with what meets the requirements of the literary process. Academician A.N. Veselovsky called this process “counter flow”. In the history of Polish-Georgian and Bulgarian-Georgian literary relations, translation occupied and occupies a paramount place today.

Линии рецепции «Записок из подполья» Ф.М. Достоевского в шведской литературе

Notes from the Underground has become a relevant text in Sweden only since the second half of the 20 th century, primarily due to the emergence of translations and criticism, but also in connection with the construction of “the people’s home” (“folkhemmet”), which is what a Swedish person thinks about when reading about Crystal Palace. However, not only social ideas attract Swedish readers in Notes from the Underground; the problems of human isolation, desire, and inability to love another person more than oneself, as well as the worldview of a “paradoxalist” are also relevant to them. The multi-layered text of Notes from the Underground has not remained unnoticed either. The article examines several instances of the Notes from the Underground reception in Swedish literature, namely social and philosophical (Sven Delblank, Lars Ahlin), socio-religious (Birgitta Trotzig), existentialist (Lars Gyllensten), and aesthetic (Lars Ahlin). It is worth mentioning that even when referring to Dostoevsky’s work in social debates, Swedish authors almost never ignore its philosophical context or reduce the universal human issues raised by the novel to the purely social issues projecting them on Swedish reality.

Origin of the 16S Ribosomal Molecule from Ancestor tRNAs

We tested the hypothesis that concatemers of ancestral tRNAs gave rise to the 16S ribosomal RNA. We built an ancestral sequence of proto-tRNAs that showed a significant identity of 51.69% and a percentage of structural identity of 0.941 with the 16S ribosomal molecule. We also propose a hypothesis for the emergence of translation.

Origin of the 16S Ribosomal Molecule from Ancestor tRNAs

We tested the hypothesis that concatemers of ancestral tRNAs gave rise to the 16S ribosomal RNA. We built an ancestral sequence of proto-tRNAs that showed a significant identity of 51.69% and a percentage of structural identity of 0.941 with the 16S ribosomal molecule. We also propose a hypothesis for the emergence of translation.

Evolutionary importance of the intramolecular pathways of hydrolysis of phosphate ester mixed anhydrides with amino acids and peptides.

Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide–phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation.

Hypothesis: Emergence of Translation as a Result of RNA Helicase Evolution

The origin of translation and the genetic code is one of the major mysteries of evolution. The advantage of templated protein synthesis could have been achieved only when the translation apparatus had already become very complex. This means that the translation machinery, as we know it today, must have evolved towards some different essential function that subsequently sub-functionalised into templated protein synthesis. The hypothesis presented here proposes that translation originated as the result of evolution of a primordial RNA helicase, which has been essential for preventing dying out of the RNA organism in sterile double-stranded form. This hypothesis emerges because modern ribosome possesses RNA helicase activity that likely dates back to the RNA world. I hypothesise that codon-anticodon interactions of tRNAs with mRNA evolved as a mechanism used by RNA helicase, the predecessor of ribosomes, to melt RNA duplexes. In this scenario, peptide bond formation emerged to drive unidirectional movement of the helicase via a molecular ratchet mechanism powered by Brownian motion. I propose that protein synthesis appeared as a side product of helicase activity. The first templates for protein synthesis were functional RNAs (ribozymes) that were unwound by the helicase, and the first synthesised proteins were of random or non-sense sequence. I further suggest that genetic code emerged to avoid this randomness. The initial genetic code thus emerged as an assignment of amino acids to codons according to the sequences of the pre-existing RNAs to take advantage of the side products of RNA helicase function.

Optimality properties of a proposed precursor to the genetic code

We calculate the optimality score of a doublet precursor to the canonical genetic code with respect to mitigating the effects of point mutations and compare our results to corresponding ones for the canonical genetic code. We find that the proposed precursor is much less optimal than that of the canonical code. Our results render unlikely the notion that the doublet precursor was an intermediate state in the evolution of the canonical genetic code. These findings support the notion that code optimality reflects evolutionary dynamics, and that if such a doublet code originally had a biochemical significance, it arose before the emergence of translation.

Is it true? Is it new? Does it matter? Towards a paradigm shift in translation and interpreting studies

Despite the widespread emergence of translations and diverse types of language mediation in contemporary society, our knowledge of the processes and operators involved in the "translation industry" is still very sketchy. With most translation scholars working within the liberal arts paradigm, research to date has tended to adopt methodologies pertaining to the humanities while overlooking more practical approaches typical of the more ‘scientific’ disciplines. This paper outlines the necessity for empirical methods that aim at gathering information regarding basic aspects of translation, ranging from typologies of translations to the operators involved in their production as well as aspects regarding end user perception. Such maps and atlases delineating the status quo of translation and interpreting would provide information for fresh insights.

On the Function of Modified Nucleosides in the RNA World

Presumably ribosome and transfer RNA (tRNA) evolved from a pre-existing function in the RNA stage of life and were secondarily adapted for protein synthesis. Various possible initial functions of the primitive ribosome (protoribosome) have been suggested.The initial function of the primitive ribosome and primitive genetic translation would have been quite similar. It is possible that, initially, both functions coexisted in the protoribosome. Given that the three-dimensional structure of ribosomal RNAs shows only minor variations throughout time, it is, then, most likely that present ribosomes can still recall (remember) the most important parts of the mechanism of their initial function.A process would have arisen to inactivate the initial function of the protoribosome without affecting genetic translation: the modification of some ribosome nucleosides.We suggest that the modifications of some rRNA nucleosides located in the catalytic center responsible for the initial function of primitive ribosomes, and of some of the tRNA nucleosides which interacted with the same center could have resulted in the inability of their recognition and secondary interaction. Thus, it is a known fact that the establishing of hydrogen bonds between modified nucleosides is rare and unstable. Therefore, the initial biological function of primitive ribosomes could have been inactivated without significantly affecting its three-dimensional structure. Therefore, without affecting the primitive translation.After the emergence of translation, some catalytic proteins (enzymes) which could modify the nucleosides of ribozymes could have arisen. In brief, we suggest that the catalytic proteins, through nucleoside modification, inactivated the catalytic RNA activity but RNA capacity to recognize and to bind other RNAs was not essentially altered. Only a few ribozymes were slightly affected by the modifications and they still maintain catalytic and binding activities. Therefore, we suggest that the proteins, through modification process, could have diminished the diverse functional capacities of the first RNA molecules. Auto-organization of the organic matter could be based on this type of interaction between macromolecules (protein and RNA).