MenT nucleotidyltransferase toxins extend tRNA acceptor stems and can be inhibited by asymmetrical antitoxin binding

Xu, Xibing; Usher, Ben; Gutierrez, Claude; Barriot, Roland; Arrowsmith, Tom J.; Han, Xue; Redder, Peter; Neyrolles, Olivier; Blower, Tim R.; Genevaux, Pierre

Abstract

Mycobacterium tuberculosis, the bacterium responsible for human tuberculosis, has a genome encoding a remarkably high number of toxin-antitoxin systems of largely unknown function. We have recently shown that the M. tuberculosis genome encodes four of a widespread, MenAT family of nucleotidyltransferase toxin-antitoxin systems. In this study we characterize MenAT1, using tRNA sequencing to demonstrate MenT1 tRNA modification activity. MenT1 activity is blocked by MenA1, a short protein antitoxin unrelated to the MenA3 kinase. X-ray crystallographic analysis shows blockage of the conserved MenT fold by asymmetric binding of MenA1 across two MenT1 protomers, forming a heterotrimeric toxin-antitoxin complex. Finally, we also demonstrate tRNA modification by toxin MenT4, indicating conserved activity across the MenT family. Our study highlights variation in tRNA target preferences by MenT toxins, selective use of nucleotide substrates, and diverse modes of MenA antitoxin activity.

Citation

Xu, X., Usher, B., Gutierrez, C., Barriot, R., Arrowsmith, T. J., Han, X., …Genevaux, P. (2023). MenT nucleotidyltransferase toxins extend tRNA acceptor stems and can be inhibited by asymmetrical antitoxin binding. Nature Communications, 14, Article 4644. https://doi.org/10.1038/s41467-023-40264-3

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2023
• Online Publication Date: Aug 17, 2023
• Publication Date: 2023
• Deposit Date: Aug 17, 2023
• Publicly Available Date: Aug 17, 2023
• Journal: Nature Communications
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Article Number: 4644
• DOI: https://doi.org/10.1038/s41467-023-40264-3
• Public URL: https://durham-repository.worktribe.com/output/1720149