<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Structural insights into regulation of gene expression"^^ . "The thesis comprises two parts investigating structural aspects of various mechanisms\r\nof translational control.\r\nThe first chapter investigates a mechanism behind ribosome stalling alleviation.\r\nPoly-proline stretches often induce ribosome stalling, which needs to be\r\nalleviated to translate the mRNA. In bacteria the ribosomes are rescued by Elongation\r\nFactor P (EF-P). EF-P is activated by diverse post-translational modifications\r\n(PTMs) of a positively charged amino acid. Such PTM is the glycosylation of\r\narginine conserved in approximately 10% of all bacterial species including severe\r\npathogens (e.g. Pseudomonas aeruginosa). The arginine is glycosylated by a glycosyltransferase\r\nEarP which attaches rhamnose to the arginine. Impairing the\r\nglycosylation reduces the pathogenicity of the bacteria. However, EarP is an uncharacterized\r\nglycosyltranferase as it is only the first documented case of arginine\r\nN-glycosylation in prokaryotes. Hence, the mechanism of EF-P rhamnosylation\r\nby EarP was investigated using nuclear magnetic resonance spectroscopy, X-ray\r\ncrystallography and various in vivo and in vitro assays. The atomic structure of\r\nEarP with its substrate dTDP-rhamnose was solved and the in vivo and in vitro\r\nassays together with subsequent studies elucidate the putative mechanism of EarP\r\nrhamnosylation thus providing basis for targeted antibiotic drug design.\r\nThe second chapter investigates the translational suppression of the hunchback\r\n(hb) mRNA. The hb mRNA forms during Drosophila development a protein gradient\r\ngoverning the anterior-posterior body axis formation. The Hunchback protein\r\ngradient results from the suppression of hb mRNA at posterior by a complex of\r\nthree proteins – Pumilio (Pum), Nanos and Brain tumor (Brat). Nanos, expressed\r\nin an opposing gradient to Hunchback, provides spatial information. Uniformly\r\nexpressed Pum and Brat are RNA binding proteins that specifically recognize the\r\nhb mRNA. The structure of Brat bound to the hb mRNA, and the structure the\r\ncomplex of Pum and Nanos bound to the hb mRNA have been previously solved.\r\nHowever, it remains unclear how exactly these three proteins assemble on the hb\r\nmRNA together, and if they are structurally and functional directly linked. The\r\ncomplex was investigated using modelling based on small-angle X-ray and neutron\r\nscattering data combined with additional restraints from cross-linking/mass\r\nspectrometry. The data were further complemented and validated by various\r\nin vitro assays such as electrophoretic mobility shift assays and isothermal titration\r\ncalorimetry. The investigation provides initial insights about the complex and\r\npaves the way for future approaches to fully elucidate the structure of the complex."^^ . "2020" . . . . . . . "Jakub"^^ . "Macošek"^^ . "Jakub Macošek"^^ . . . . . . "Structural insights into regulation of gene expression (PDF)"^^ . . . "macosek_dissertation.pdf"^^ . . . "Structural insights into regulation of gene expression (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #27575 \n\nStructural insights into regulation of gene expression\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .