Gradual compaction of the nascent peptide during cotranslational folding on the ribosome
| Autor: | Ekaterina Samatova, Marina V. Rodnina, Marija Liutkute, Manisankar Maiti, Jörg Enderlein |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Protein Folding QH301-705.5 Science PET-FCS Peptide Fluorescence correlation spectroscopy 010402 general chemistry 01 natural sciences Ribosome General Biochemistry Genetics and Molecular Biology HemK 03 medical and health sciences Biochemistry and Chemical Biology Protein Methyltransferases Biology (General) nascent chain dynamics 030304 developmental biology chemistry.chemical_classification 0303 health sciences General Immunology and Microbiology Force profile General Neuroscience Escherichia coli Proteins General Medicine Ribosomal RNA 0104 chemical sciences 030104 developmental biology Spectrometry Fluorescence chemistry ribosome Protein Biosynthesis Biophysics Medicine Protein folding cotranslational folding Peptides Ribosomes Research Article |
| Zdroj: | eLife, Vol 9 (2020) eLife |
| Popis: | Nascent polypeptides begin to fold in the constrained space of the ribosomal peptide exit tunnel. Here we use force-profile analysis (FPA) and photo-induced energy-transfer fluorescence correlation spectroscopy (PET-FCS) to show how a small α-helical domain, the N-terminal domain of HemK, folds cotranslationally. Compaction starts vectorially as soon as the first α-helical segments are synthesized. As nascent chain grows, emerging helical segments dock onto each other and continue to rearrange at the vicinity of the ribosome. Inside or in the proximity of the ribosome, the nascent peptide undergoes structural fluctuations on the µs time scale. The fluctuations slow down as the domain moves away from the ribosome. Mutations that destabilize the packing of the domain’s hydrophobic core have little effect on folding within the exit tunnel, but abolish the final domain stabilization. The results show the power of FPA and PET-FCS in solving the trajectory of cotranslational protein folding and in characterizing the dynamic properties of folding intermediates. |
| Databáze: | OpenAIRE |
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