Structures of KEOPS bound to tRNA reveal functional roles of the kinase Bud32.

Autor: Ona Chuquimarca SM; Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada., Beenstock J; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada. beenstock@lunenfeld.ca., Daou S; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada., Porat J; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada., Keszei AFA; Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, M5G 2C4, Canada., Yin JZ; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada.; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada., Beschauner T; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada.; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada., Bayfield MA; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada., Mazhab-Jafari MT; Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, M5G 2C4, Canada., Sicheri F; Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada. sicheri@lunenfeld.ca.; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada. sicheri@lunenfeld.ca.; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada. sicheri@lunenfeld.ca.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Dec 05; Vol. 15 (1), pp. 10633. Date of Electronic Publication: 2024 Dec 05.
DOI: 10.1038/s41467-024-54787-w
Abstrakt: The enzyme complex KEOPS (Kinase, Endopeptidase and Other Proteins of Small size) installs the universally conserved and essential N 6 -threonylcarbamoyl adenosine modification (t 6 A) on ANN-decoding tRNAs in eukaryotes and in archaea. KEOPS consists of Cgi121, Kae1, Pcc1, Gon7 and the atypical kinase/ATPase Bud32. Except Gon7, all KEOPS subunits are needed for tRNA modification, and in humans, mutations in all five genes underlie the lethal genetic disease Galloway Mowat Syndrome (GAMOS). Kae1 catalyzes the modification of tRNA, but the specific contributions of Bud32 and the other subunits are less clear. Here we solved cryogenic electron microscopy structures of KEOPS with and without a tRNA substrate. We uncover distinct flexibility of KEOPS-bound tRNA revealing a conformational change that may enable its modification by Kae1. We further identified a contact between a flipped-out base of the tRNA and an arginine residue in C-terminal tail of Bud32 that correlates with the conformational change in the tRNA. We also uncover contact surfaces within the KEOPS-tRNA holo-enzyme substrate complex that are required for Bud32 ATPase regulation and t 6 A modification activity. Our findings uncover inner workings of KEOPS including a basis for substrate specificity and why Kae1 depends on all other subunits.
Competing Interests: Competing interests: The authors declare no competing interests.
(© 2024. The Author(s).)
Databáze: MEDLINE
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