Download MendeleyCatalytic and regulatory basis of tRNA t 6 A modification by the KEOPS complex.
Zhou, L., Zhang, Z., Jin, M., Xie, D., Wen, H., Westhof, E., Lei, D., Zhang, W.(2026) Nat Commun
- PubMed: 42140986 Search on PubMed
- DOI: https://doi.org/10.1038/s41467-026-73296-6
- Primary Citation Related Structures:
9X4G, 9X4H - PubMed Abstract:
N 6 -threonylcarbamoyladenosine (t 6 A) at tRNA position 37 is essential for translational fidelity and cellular homeostasis. The multi-subunit KEOPS complex catalyzes t 6 A formation in Archaea and Eukarya. Here we present cryo-EM structures of C. elegans KEOPS in its apo and tRNA-bound states. tRNA binding induces concerted conformational rearrangements, distorting the anticodon loop to project A37 into the Kae1 active site. Kae1 recognizes the conserved G10-C25 pair and 36-UAA-38 motif. Bud32 directly contacts the anticodon and acceptor arms, coupling ATP hydrolysis to t 6 A catalysis in the distant Kae1 active site through long-range conformational changes. Cgi121 enhances catalytic efficiency through cooperative binding with Bud32 and the tRNA 3' CCA. Pcc1 stabilizes the anticodon loop and mediates KEOPS dimerization, enhancing tRNA binding and t 6 A activity. GAMOS-associated mutations cluster at functional hotspots within the KEOPS-tRNA complex. This study provides a structural framework for understanding KEOPS mechanism and its cellular roles.
- School of Life Sciences, State Key Laboratory of Natural Product Chemistry, Lanzhou University, Lanzhou, China.
Organizational Affiliation:
