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11	Non-Canonical Grammar!? Lange, Claudia, Rütten, Tanja 22 July 2020 (has links) The papers collected in this special issue originated from a workshop held at the Annual Meeting of German University Teachers of English (Anglistentag) in Hamburg in September 2016. Contributors and participants at the workshop were invited to probe into the usefulness – and the limitations – of the notion noncanonical grammar for their respective fields of interest, and the present volume is a lively testimony to an engaging discussion. info:eu-repo/classification/ddc/820 ddc:820
12	Funkční studie potenciální nukleotidázy kódované genem spr1057 Streptococcus pneumoniae, homologa proteinu YjjG E. coli / Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a homologue of Escherichia coli protein YjjG Vacková, Zuzana January 2010 (has links) ANGLICKÝ ABSTRAKT Functional study of the putative nucleotidase encoded by spr1057 gene in Streptococcus pneumoniae, a likely homolog of Escherichia coli protein YjjG. Bacterial cells are constantly exposed to innumerable toxic substances, either in their external environment or by by-products of their own metabolism. For these reasons, the bacterial cells evolved several mechanisms to cope with this challenge. These mechanisms are represented by: blocking the uptake, export by specific transporters as well as specific inactivation of these substance by enzymes. A particular group of these toxic substances are noncanonica nucleotides, which can directly inhibit bacterial cell DNA replication or can result in increased mutation rate. Enzymes recognizing these modified derivatives are known as "house-cleaning" nucleotide phsphateses, which can inactivate the potentially mutagenic nucleotides and prevent their incorporation into DNA and RNA. Some of the "house- cleaning" enzymes belong to a group of haloacid dehalogenase enzymes (haloacid dehalogenase-like hydrolase superfamily), which are found in many bacterial species. This thesis is focused on the function of hypothetical protein Spr1057 of Streptococcus pneumoniae with an unknown function. Sequence comparison revealed that Spr1057 has a significant...
13	Orthogonality and Codon Preference of the Pyrrolysyl-tRNA Synthetase-tRNAPyl pair in Escherichia coli for the Genetic Code Expansion Odoi, Keturah 2012 May 1900 (has links) Systematic studies of basal nonsense suppression, orthogonality of tRNAPyl variants, and cross recognition between codons and tRNA anticodons are reported. E. coli displays detectable basal amber and opal suppression but shows a negligible ochre suppression. Although detectable, basal amber suppression is fully inhibited when a pyrrolysyl-tRNA synthetase (PylRS)-tRNAPyl_CUA pair is genetically encoded. trnaPyl_CUA is aminoacylated by an E. coli aminoacyl-tRNA synthetase at a low level, however, this misaminoacylation is fully inhibited when both PylRS and its substrate are present. Besides that it is fully orthogonal in E. coli and can be coupled with PylRS to genetically incorporate a NAA at an ochre codon, tRNAPyl_UUA is not able to recognize an UAG codon to induce amber suppression. This observation is in direct conflict with the wobble base pair hypothesis and enables using an evolved M. jannaschii tyrosyl-tRNA synthetase-tRNAPyl_UUA pair and the wild type or evolved PylRS-tRNAPyl_UUA pair to genetically incorporate two different NAAs at amber and ochre codons. tRNAPyl_UCA is charged by E. coli tryptophanyl-tRNA synthetase, thus not orthogonal in E. coli. Mutagenic studies of trnaPyl_UCA led to the discovery of its G73U form which shows a higher orthogonality. Mutating trnaPyl_CUA to trnaPyl_UCCU not only leads to the loss of the relative orthogonality of tRNAPyl in E. coli but also abolishes its aminoacylation by PylRS. Pyl, pyrrolysine PylRS, pyrrolysyl-tRNA synthetase NAA, noncanonical amino acid aaRS, aminoacyl-tRNA synthetase T4 PNK, T4 polynucleotide kinase AzF, para-azido-L-phenylalanine PCR, polymerase chain reaction RF, release factor TrpRS, tryptophanyl-tRNA synthetase ArgRS, arginyl-tRNA synthetase Trp, tryptophan Lys, lysine Glu, glutamate Gln, glutamine Phe, phenylalanine Arg, arginine.

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