9FHL

High-resolution cryo-EM structure of Saccharolobus solfataricus 30S ribosomal subunit bound to mRNA and initiator tRNA

Summary for 9FHL

• Entry DOI: 10.2210/pdb9fhl/pdb
• EMDB information: 50445
• Descriptor: rRNA 16S Sso, Small ribosomal subunit protein uS8, Small ribosomal subunit protein eS8, ... (39 entities in total)
• Functional Keywords: 30s, ribosome, translation, saccharolobus solfataricus
• Biological source: Saccharolobus solfataricus P2; More
• Total number of polymer chains: 35
• Total formula weight: 1008013.60

Authors

Bourgeois, G.,Coureux, P.D.,Mechulam, Y.,Schmitt, E. (deposition date: 2024-05-27, release date: 2025-01-15)

Primary citation

Bourgeois, G.,Coureux, P.D.,Lazennec-Schurdevin, C.,Madru, C.,Gaillard, T.,Duchateau, M.,Chamot-Rooke, J.,Bourcier, S.,Mechulam, Y.,Schmitt, E.
Structures of Saccharolobus solfataricus initiation complexes with leaderless mRNAs highlight archaeal features and eukaryotic proximity.
Nat Commun, 16:348-348, 2025

PubMed 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.

PubMed: 39753558
DOI: 10.1038/s41467-024-55718-5

Experimental method

ELECTRON MICROSCOPY (2.5 Å)