9HN9

Mouse QTRT1/2 in complex with mouse pre-tRNA-Tyr-1-4

Summary for 9HN9

• Entry DOI: 10.2210/pdb9hn9/pdb
• EMDB information: 52308 52309
• Descriptor: Queuine tRNA-ribosyltransferase catalytic subunit 1, Queuine tRNA-ribosyltransferase accessory subunit 2, mouse pre-tRNA-Tyr-1-4, ... (4 entities in total)
• Functional Keywords: queuosine, trna, qtrt1/2, trna modification, rna binding protein
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 3
• Total formula weight: 119948.03

Authors

Kaczmarczyk, I.,Koziej, L.,Glatt, S. (deposition date: 2024-12-10, release date: 2025-08-13)

Primary citation

Guo, W.,Kaczmarczyk, I.,Kopietz, K.,Flegler, F.,Russo, S.,Cigirgan, E.,Chramiec-Glabik, A.,Koziej, L.,Cirzi, C.,Peschek, J.,Reuter, K.,Helm, M.,Glatt, S.,Tuorto, F.
Queuosine is incorporated into precursor tRNA before splicing.
Nat Commun, 16:7044-7044, 2025

PubMed Abstract: Each newly transcribed tRNA molecule must undergo processing and receive modifications to become functional. Queuosine (Q) is a tRNA modification present at position 34 of four tRNAs with "GUN" anticodons. Among these, the precursor of tRNA carries an intronic sequence within the anticodon loop that is removed by an essential non-canonical splicing event. The functional and temporal coupling between tRNA-splicing and Q-incorporation remains elusive. Here, we demonstrate in vitro and in vivo that intron-containing precursors of tRNA are modified with Q or with the Q-derivative galactosyl-queuosine (galQ) before being spliced. We show that this order of events is conserved in mouse, human, flies and worms. Using single particle cryo-EM, we confirm that pre-tRNA is a bona fide substrate of the QTRT1/2 complex, which catalyzes the incorporation of Q into the tRNA. Our results elucidate the hierarchical interplay that coordinates Q-incorporation and splicing in eukaryotic tRNAs, providing a relevant but unappreciated aspect of the cellular tRNA maturation process.

PubMed: 40745156
DOI: 10.1038/s41467-025-62220-z

Experimental method

ELECTRON MICROSCOPY (3.1 Å)