5JBH
Cryo-EM structure of a full archaeal ribosomal translation initiation complex in the P-IN conformation
Summary for 5JBH
| Entry DOI | 10.2210/pdb5jbh/pdb |
| EMDB information | 8149 |
| Descriptor | 16S ribosomal RNA, 30S ribosomal protein eS28, 30S ribosomal protein eS27, ... (40 entities in total) |
| Functional Keywords | transcription |
| Biological source | Pyrococcus abyssi GE5 More |
| Total number of polymer chains | 36 |
| Total formula weight | 1065147.63 |
| Authors | Coureux, P.-D.,Schmitt, E.,Mechulam, Y. (deposition date: 2016-04-13, release date: 2016-12-07, Last modification date: 2024-06-12) |
| Primary citation | Coureux, P.D.,Lazennec-Schurdevin, C.,Monestier, A.,Larquet, E.,Cladiere, L.,Klaholz, B.P.,Schmitt, E.,Mechulam, Y. Cryo-EM study of start codon selection during archaeal translation initiation. Nat Commun, 7:13366-13366, 2016 Cited by PubMed Abstract: Eukaryotic and archaeal translation initiation complexes have a common structural core comprising e/aIF1, e/aIF1A, the ternary complex (TC, e/aIF2-GTP-Met-tRNA) and mRNA bound to the small ribosomal subunit. e/aIF2 plays a crucial role in this process but how this factor controls start codon selection remains unclear. Here, we present cryo-EM structures of the full archaeal 30S initiation complex showing two conformational states of the TC. In the first state, the TC is bound to the ribosome in a relaxed conformation with the tRNA oriented out of the P site. In the second state, the tRNA is accommodated within the peptidyl (P) site and the TC becomes constrained. This constraint is compensated by codon/anticodon base pairing, whereas in the absence of a start codon, aIF2 contributes to swing out the tRNA. This spring force concept highlights a mechanism of codon/anticodon probing by the initiator tRNA directly assisted by aIF2. PubMed: 27819266DOI: 10.1038/ncomms13366 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (5.34 Å) |
Structure validation
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