Translation errors

A more accurate replication required protein enzymes, but the synthesis of these enzymes required a primitive translation apparatus, and therefore the presence of genes for such an apparatus. The smallest genome that is capable of coding for a replicase and a rudimentary translation apparatus is not known, but it has been estimated that a minimum of ten genes is necessary in order to keep translation errors within tolerable limits. The appearance of a primitive genome presents, however, two contrasting problems. 

In the development of proteins as therapeutic agents, it is crucial to ensure the homogeneity of the potential products. However, a survey of the current literature has indicated that overexpression of recombinant proteins in E. coli often leads to translational errors as well as post-translational modifications (1). Acetylation of the e-amino group of lysyl residues in bovine somatotropin has been documented (2). Substitution of methionine by norleucine is another well known example (3,4). 

The zinc site is less well suited to discrimination against serine because this amino acid does have a hydroxyl group that can bind to the zinc. Indeed, with only this mechanism available, threonyl-tRNA synthetase does mistakenly couple serine to threonyl-tRNA at a rate 10 2 to 10 3 times that for threonine. As noted in Section 29. LL this error rate is likely to lead to many translation errors. How is a higher level of specificity achieved ... 

Amongst the most widely used purine derivatives are 8-oxo-dG and 2-aminopurine (2AP). As the persistence of damaged DNA/RNA bases could lead to transcriptional/translational errors, organisms have evolved mechanisms to recognise such lesions. E. coli possesses proteins that specifically bind to RNA carrying 8-oxoguanosine. The effect of introducing 8-oxo-dG into telomeric... 

The Code mentions 382 synthetic additives, comprizing 69 individual flavouring substances and the following 18 chemical groups ketones, lactones, aromatic aldehydes, aromatic alcohols, esters, ethers, isothiocyanates, indole and its derivatives, fatty acids, aliphatic aldehydes, aliphatic alcohol, aliphatic hydrogen carbide aldehydes, (translation error, probably hydrocarbons), thio alcohols, thio ethers, terpene hydrocarbons, phenols, phenolethers, furfural and its derivatives. 

On receiving the reports those that fell outside the chemicals sector were put to one side. These included those companies predominantly in the life sciences, oil/energy, and metals/minerals sectors. At this stage, in order to provide a reasonably balanced picture, additional effort was made to obtain reports from the main players. Since the USA and Europe were well represented, effort was also made to obtain reports from other geographical areas. To avoid translation errors only reports issued in English were analysed. 

Errors made during protein translation can result in misfolded proteins, which represent a burden to the cell. Mutations that make a protein more susceptible to error-induced misfolding will result in a loss of fitness. If the mutation occurs in a highly expressed protein, then translational errors (and misfolding events) will be more common, resulting in a larger fitness loss. Hence, protein expression will scale directly with selective constraint, and inversely with evolutionary rate [11]. 

Language (particularly to avoid marketplace translation errors)... 

Frequency displacement The end-to-end shift in frequency that may result from independent frequency translation errors in a circuit. 

Note that each generated text will accord exactly with the underlying specification knowledge repository because there is no manual involvement in its production. If exact accordance is not obtained, this can only be because of a translator error once corrected, tliat error vanishes for all time and so the translation quality improves steadily rather tlian remaining constant. 

In contrast to Mg + and Mn +, which stabilize secondary structures in DNA and RNA, Cu + destabilizes DNA and RNA double helices, and this is attributed to the ability of copper to bind to the nucleic acid bases. Chao and Kearns have recently explored the possibility that this binding, as detected by electron and nuclear magnetic resonance spectroscopy, might be used to probe certain structural features of nucleic acid molecules, such as the looped out regions of tRNAs. The nature of the Cu complexes formed with nucleosides and nucleotides varies with the specific nucleic acid derivatives used and also the pH. Thus, in the pH range 8.5—10.0, copper forms a water-soluble complex with the ribose OH groups of the ribonu-cleosides and 5 -ribonucleotides, but these complexes cannot form with any of the deoxynucleosides or the 2 - and 3 -ribonucleotides. It is suggested that copper(ii) could stabilize unusual polynucleotide structures or interactions in certain enzymatic systems the latter could, for example, be responsible for translational errors in the RNA,DNA polymerase system which are known to be induced by transition metals. 

Dukan S, Farewell A, Ballesteros M et al. (2000) Protein oxidation in response to increased transcriptional or translational errors. Proc Natl Acad Sci USA 97( 11), 5746-5749. 

This process can cover the risks of translation errors of the information issued by the study agent from the signal post program, from the technical plan and finally the file interpreted by the MEI target. 

Jelenc, P.C., and Kurland, C.G., 1979, Nucleotide triphosphate regeneration decreases the frequency of translation errors,... 

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