7AQC
Structure of the bacterial RQC complex (Decoding State)
Summary for 7AQC
| Entry DOI | 10.2210/pdb7aqc/pdb |
| Related | 7AQD |
| EMDB information | 11862 |
| Descriptor | 23S ribosomal RNA, 50S ribosomal protein L14, 50S ribosomal protein L15, ... (33 entities in total) |
| Functional Keywords | ribosome, rqch, rqc, rqc2, hsp15, fibronectin-binding protein, nemf, ribosome-associated quality control, ribosome-associated, 50s, alanine-tailing |
| Biological source | Bacillus subtilis subsp. subtilis str. 168 More |
| Total number of polymer chains | 34 |
| Total formula weight | 1427904.68 |
| Authors | Filbeck, S.,Pfeffer, S. (deposition date: 2020-10-21, release date: 2020-11-25, Last modification date: 2024-05-01) |
| Primary citation | Filbeck, S.,Cerullo, F.,Paternoga, H.,Tsaprailis, G.,Joazeiro, C.A.P.,Pfeffer, S. Mimicry of Canonical Translation Elongation Underlies Alanine Tail Synthesis in RQC. Mol.Cell, 81:104-, 2021 Cited by PubMed Abstract: Aborted translation produces large ribosomal subunits obstructed with tRNA-linked nascent chains, which are substrates of ribosome-associated quality control (RQC). Bacterial RqcH, a widely conserved RQC factor, senses the obstruction and recruits tRNA to modify nascent-chain C termini with a polyalanine degron. However, how RqcH and its eukaryotic homologs (Rqc2 and NEMF), despite their relatively simple architecture, synthesize such C-terminal tails in the absence of a small ribosomal subunit and mRNA has remained unknown. Here, we present cryoelectron microscopy (cryo-EM) structures of Bacillus subtilis RQC complexes representing different Ala tail synthesis steps. The structures explain how tRNA is selected via anticodon reading during recruitment to the A-site and uncover striking hinge-like movements in RqcH leading tRNA into a hybrid A/P-state associated with peptidyl-transfer. Finally, we provide structural, biochemical, and molecular genetic evidence identifying the Hsp15 homolog (encoded by rqcP) as a novel RQC component that completes the cycle by stabilizing the P-site tRNA conformation. Ala tailing thus follows mechanistic principles surprisingly similar to canonical translation elongation. PubMed: 33259811DOI: 10.1016/j.molcel.2020.11.001 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.99 Å) |
Structure validation
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