Tiarins, a diverse family of natural Trojan-horse aminoacyl-tRNA synthetase inhibitors discovered by genome mining

Travin, D. Y.; Livensky, A.; Bikmetov, D.; Pavlov, C.; Serebryakova, M.; Gilep, K.; Wu, F.; Naquin, D.; Timchenko, T.; Lippens, G.; Zirah, S.; Mergaert, P.; Dubiley, S.

doi:10.64898/2025.12.02.691738

bioRxiv · 10.64898/2025.12.02.691738

Tiarins, a diverse family of natural Trojan-horse aminoacyl-tRNA synthetase inhibitors discovered by genome mining

Travin, D. Y.·Livensky, A.·Bikmetov, D.·Pavlov, C.·Serebryakova, M.·Gilep, K.·Wu, F.·Naquin, D.·Timchenko, T.·Lippens, G.·Zirah, S.·Mergaert, P.·Dubiley, S.

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Abstract

Trifolitoxin (TFX) is a ribosomally synthesized and post-translationally modified peptide antibiotic produced by Rhizobium anhuiense T24. Although discovered more than half a century ago, its mechanism of action has remained elusive. Here we demonstrate that TFX inhibits arginyl-tRNA synthetase (ArgRS), an essential translation enzyme. TFX acts as a Trojan-horse antibiotic: it enters cells via the inner membrane oligopeptide transporter YejABEF and then undergoes partial proteolysis by the aminopeptidase PepN to release a "warhead" that binds ArgRS and arrests translation. A systematic analysis of prokaryotic genomes revealed that TFX belongs to a widespread family of modified peptides that we designate the tiarins. In addition to ArgRS inhibitors, the tiarin family includes compounds that specifically target at least seven other aminoacyl-tRNA synthetases. These findings define a previously unrecognized family of natural antibiotics and provide a framework for developing a new class of inhibitors targeting various tRNA synthetases.

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Travin, D. Y., Livensky, A., Bikmetov, D., Pavlov, C., Serebryakova, M., Gilep, K., Wu, F., Naquin, D., Timchenko, T., Lippens, G., Zirah, S., Mergaert, P., Dubiley, S.. 2025-12-02. Tiarins, a diverse family of natural Trojan-horse aminoacyl-tRNA synthetase inhibitors discovered by genome mining. https://doi.org/10.64898/2025.12.02.691738

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