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-Structure paper
タイトル | Visualization of translation and protein biogenesis at the ER membrane. |
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ジャーナル・号・ページ | Nature, Vol. 614, Issue 7946, Page 160-167, Year 2023 |
掲載日 | 2023年1月25日 |
著者 | Max Gemmer / Marten L Chaillet / Joyce van Loenhout / Rodrigo Cuevas Arenas / Dimitrios Vismpas / Mariska Gröllers-Mulderij / Fujiet A Koh / Pascal Albanese / Richard A Scheltema / Stuart C Howes / Abhay Kotecha / Juliette Fedry / Friedrich Förster / |
PubMed 要旨 | The dynamic ribosome-translocon complex, which resides at the endoplasmic reticulum (ER) membrane, produces a major fraction of the human proteome. It governs the synthesis, translocation, membrane ...The dynamic ribosome-translocon complex, which resides at the endoplasmic reticulum (ER) membrane, produces a major fraction of the human proteome. It governs the synthesis, translocation, membrane insertion, N-glycosylation, folding and disulfide-bond formation of nascent proteins. Although individual components of this machinery have been studied at high resolution in isolation, insights into their interplay in the native membrane remain limited. Here we use cryo-electron tomography, extensive classification and molecular modelling to capture snapshots of mRNA translation and protein maturation at the ER membrane at molecular resolution. We identify a highly abundant classical pre-translocation intermediate with eukaryotic elongation factor 1a (eEF1a) in an extended conformation, suggesting that eEF1a may remain associated with the ribosome after GTP hydrolysis during proofreading. At the ER membrane, distinct polysomes bind to different ER translocons specialized in the synthesis of proteins with signal peptides or multipass transmembrane proteins with the translocon-associated protein complex (TRAP) present in both. The near-complete atomic model of the most abundant ER translocon variant comprising the protein-conducting channel SEC61, TRAP and the oligosaccharyltransferase complex A (OSTA) reveals specific interactions of TRAP with other translocon components. We observe stoichiometric and sub-stoichiometric cofactors associated with OSTA, which are likely to include protein isomerases. In sum, we visualize ER-bound polysomes with their coordinated downstream machinery. |
リンク | Nature / PubMed:36697828 / PubMed Central |
手法 | EM (サブトモグラム平均) / EM (単粒子) |
解像度 | 2.9 - 9.3 Å |
構造データ | EMDB-15870, PDB-8b6l: EMDB-15871: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Decoding-Sampling State EMDB-15872: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Classical Pre+ State EMDB-15873: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Classical Pre State EMDB-15874: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Rotated-1 Pre+ State EMDB-15875: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Rotated-1 Pre State EMDB-15876: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Rotated-2 Pre State EMDB-15877: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Translocation State EMDB-15878: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Post State EMDB-15879: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Non-Rotated Hibernating State EMDB-15880: Subtomogram Average of Soluble and ER Membrane-Associated Ribosomes in the Rotated Hibernating State EMDB-15884: Subtomogram Average of the Ribosome-Sec61-TRAP-OSTA-Translocon Complex EMDB-15885: Subtomogram Average of the Ribosome-Sec61-TRAP-Translocon Complex EMDB-15886: Subtomogram Average of the Ribosome-Sec61-TRAP-Multipass-Translocon Complex EMDB-15887: Subtomogram Average of the Ribosome-Sec61-Multipass-Translocon Complex EMDB-15888: Subtomogram Average of the Ribosome-EBP1 Complex EMDB-15889: Subtomogram Average of the Idle Ribosome-Sec61-TRAP-OSTA-Translocon Complex EMDB-15890: Subtomogram Average of the Sec61-TRAP-OSTA Translocon EMDB-15891: Subtomogram Average of the Sec61-TRAP-OSTA-L1 Translocon EMDB-15892: Subtomogram Average of the Sec61-TRAP-OSTA-L2 Translocon EMDB-15893, PDB-8b6z: |
由来 |
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キーワード | MEMBRANE PROTEIN / membrane protein complex / protein translocation / N-glycosylation / signal peptide insertion / RIBOSOME / translation / protein biogenesis / elongation factor |