Sökning: "peptidyl transfer"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden peptidyl transfer.

1. 1. Ribosomal Peptidyl Transfer with Natural and Unnatural Amino Acids

   Författare :Ka-Weng Ieong; Uppsala universitet; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER

3. 2. Computer simulations of ribosome reactions

   Författare :Stefan Trobro; Johan Åqvist; Arieh Warshel; Uppsala universitet; []
   Nyckelord :Molecular biology; ribosomal termination; Empirical valence bond; peptidyl transfer; Molekylärbiologi;

   Sammanfattning : Peptide bond formation and translational termination on the ribosome have been simulated by molecular mechanics, free energy perturbation, empirical valence bond (MD/FEP/EVB) and automated docking methods. Recent X-ray crystallographic data is used here to calculate the entire free energy surface for the system complete with substrates, ribosomal groups, solvent molecules and ions. LÄS MER

4. 3. Rate and Accuracy of Bacterial Protein Synthesis

   Författare :Magnus Johansson; Måns Ehrenberg; Jon Lorsch; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; protein synthesis; ribosome; peptidyl transfer; rate-accuracy trade-off; kinetics; Biology with specialization in Molecular Biotechnology; Biologi med inriktning mot molekylär bioteknik;

   Sammanfattning : High levels of accuracy in transcription, aminoacylation of tRNA, and mRNA translation are essential for all life forms. However, high accuracy also necessarily means large energy dissipation and slow kinetics. Therefore, in vivo there is a fine tuned balance between rate and accuracy of key chemical reactions. LÄS MER

5. 4. Wobble modifications and other features in transfer RNA important for decoding and reading frame maintenance

   Författare :Joakim Näsvall; Glenn Björk; Michael O'Connor; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Transfer RNA; Modified nucleosides; Decoding; Reading frame maintenance; Molecular biology; Molekylärbiologi;

   Sammanfattning : Transfer RNA (tRNA) is the adaptor molecule responsible for bringing the correct amino acid to the ribosome during protein synthesis. tRNA contains a number of modified nucleosides, which are derivatives of the four normal nucleosides. LÄS MER

7. 5. Rate and Accuracy of Bacterial Protein Synthesis with Natural and Unnatural Amino Acids

   Författare :Ka-Weng Ieong; Måns Ehrenberg; Simpson Joseph; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ribosome; protein synthesis; translation; efficiency-accuracy trade-off; kinetics; unnatural amino acids; Molecular Biology; Molekylärbiologi;

   Sammanfattning : This thesis addresses different questions regarding the rate, efficiency, and accuracy of peptide bond formation with natural as well as unnatural amino acids: Which step is rate-limiting during peptide bond formation? How does the accuracy vary with different transfer RNAs (tRNAs) and codons and how is it relevant to the living cells? Does proofreading selection of codon reading occur in a single- or multi-step manner as theoretically suggested? How does the E. coli translation system discriminate unnatural amino acids? Based on that, how to improve the incorporation efficiencies of unnatural amino acids?Based on the study on pH dependence of peptide bond formation, we show that the rate of the chemistry of peptidyl transfer to aminoacyl-tRNA (AA-tRNA) Gly-tRNAGly or Pro-tRNAPro limits the rate of peptide bond formation at physiological pH 7. LÄS MER