EMD-50717

Single-particle
2.97 Å
EMD-50717 Deposition: 19/06/2024
Map released: 15/01/2025
Last modified: 15/01/2025
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-50717

Cryo-EM structure of Saccharolobus solfataricus 30S initiation complex bound to SD mRNA with h44 in up position

EMD-50717

Single-particle
2.97 Å
EMD-50717 Deposition: 19/06/2024
Map released: 15/01/2025
Last modified: 15/01/2025
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Saccharolobus solfataricus P2, Escherichia coli, Pyrococcus abyssi
Sample: High-resolution cryo-EM structure of Saccharolobus solfataricus 30S ribosomal subunit bound to mRNA and initiator tRNA
Fitted models: 9frl (Avg. Q-score: 0.471)

Deposition Authors: Bourgeois G, Coureux PD, Mechulam Y , Schmitt E
Structures of Saccharolobus solfataricus initiation complexes with leaderless mRNAs highlight archaeal features and eukaryotic proximity.
PUBMED: 39753558
DOI: doi:10.1038/s41467-024-55718-5
ISSN: 2041-1723
Abstract:
The archaeal ribosome is of the eukaryotic type. TACK and Asgard superphyla, the closest relatives of eukaryotes, have ribosomes containing eukaryotic ribosomal proteins not found in other archaea, eS25, eS26 and eS30. Here, we investigate the case of Saccharolobus solfataricus, a TACK crenarchaeon, using mainly leaderless mRNAs. We characterize the small ribosomal subunit of S. solfataricus bound to SD-leadered or leaderless mRNAs. Cryo-EM structures show eS25, eS26 and eS30 bound to the small subunit. We identify two ribosomal proteins, aS33 and aS34, and an additional domain of eS6. Leaderless mRNAs are bound to the small subunit with contribution of their 5'-triphosphate group. Archaeal eS26 binds to the mRNA exit channel wrapped around the 3' end of rRNA, as in eukaryotes. Its position is not compatible with an SD:antiSD duplex. Our results suggest a positive role of eS26 in leaderless mRNAs translation and possible evolutionary routes from archaeal to eukaryotic translation.