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-Structure paper
タイトル | Extensive ribosome and RF2 rearrangements during translation termination. |
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ジャーナル・号・ページ | Elife, Vol. 8, Year 2019 |
掲載日 | 2019年9月12日 |
著者 | Egor Svidritskiy / Gabriel Demo / Anna B Loveland / Chen Xu / Andrei A Korostelev / |
PubMed 要旨 | Protein synthesis ends when a ribosome reaches an mRNA stop codon. Release factors (RFs) decode the stop codon, hydrolyze peptidyl-tRNA to release the nascent protein, and then dissociate to allow ...Protein synthesis ends when a ribosome reaches an mRNA stop codon. Release factors (RFs) decode the stop codon, hydrolyze peptidyl-tRNA to release the nascent protein, and then dissociate to allow ribosome recycling. To visualize termination by RF2, we resolved a cryo-EM ensemble of 70S•RF2 structures at up to 3.3 Å in a single sample. Five structures suggest a highly dynamic termination pathway. Upon peptidyl-tRNA hydrolysis, the CCA end of deacyl-tRNA departs from the peptidyl transferase center. The catalytic GGQ loop of RF2 is rearranged into a long β-hairpin that plugs the peptide tunnel, biasing a nascent protein toward the ribosome exit. Ribosomal intersubunit rotation destabilizes the catalytic RF2 domain on the 50S subunit and disassembles the central intersubunit bridge B2a, resulting in RF2 departure. Our structures visualize how local rearrangements and spontaneous inter-subunit rotation poise the newly-made protein and RF2 to dissociate in preparation for ribosome recycling. |
リンク | Elife / PubMed:31513010 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.3 - 4.2 Å |
構造データ | EMDB-20048, PDB-6ofx: EMDB-20052, PDB-6og7: EMDB-20056, PDB-6ogf: EMDB-20057, PDB-6ogg: EMDB-20058, PDB-6ogi: |
化合物 | ChemComp-FME: |
由来 |
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キーワード | RIBOSOME / Ribosome recycling / translation termination / RF2 / intersubunit rotation |