{
  "abstract": "Ribosome-targeting toxins typically recognize and attack their substrates directly. Here, we provide the functional characterization of SRLase1, a widespread member of a recently identified RNase superfamily, and show that it cleaves the sarcin-ricin loop (SRL) of 23S rRNA. Unlike previously described ribosome-targeting toxins, SRLase1 requires the host elongation factor Tu (EF-Tu) for activity. EF-Tu normally engages the ribosome as part of the aminoacyl-tRNA delivery cycle, but SRLase1 instead exploits this factor through a mechanism incompatible with canonical ternary-complex formation. This host-factor-assisted mechanism reveals a distinct strategy for translation inhibition, in which a toxin repurposes a conserved component of the elongation machinery to access a vulnerable ribosomal target. Homologs of SRLase1 are widespread across bacterial phyla and are frequently encoded in conflict-associated genomic loci. Together, these findings define a widespread family of SRL-targeting toxins, expand the mechanistic repertoire of ribosomal antibacterial toxins, and demonstrate how conserved components of the host translation machinery can be co-opted to promote toxin activity.",
  "abstract_shown": true,
  "affiliations": [
    "The University of Texas at Austin"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "name": "J. T. Hespanhol"
    },
    {
      "name": "T. M. Blackburn"
    },
    {
      "name": "K. Pham"
    },
    {
      "name": "A. Varshney"
    },
    {
      "name": "G. G. Nicastro"
    },
    {
      "name": "R. F. de Souza"
    },
    {
      "name": "L. Aravind"
    },
    {
      "name": "A. Johnson"
    },
    {
      "name": "K. C. Keiler"
    },
    {
      "name": "C. M. Dunham"
    },
    {
      "affs": [
        0
      ],
      "name": "E. Bayer-Santos"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2h2akg3kh0qc2.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.18.752725",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.18.752725v1.full",
  "id": "2h2akg3kh0qc2",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.18.752725v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "microbiology"
    ],
    [
      "openalex",
      "1312|RNA and protein synthesis mechanisms"
    ]
  ],
  "openalex": "W7213749071",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.18.752725v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-18",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2h2akg3kh0qc2.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "10.64898/2026.09.18.752725",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.18.752725v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "An RNase Toxin Hijacks Elongation Factor-Tu to Cleave the Ribosomal Sarcin-Ricin Loop",
  "title_text": "An RNase Toxin Hijacks Elongation Factor-Tu to Cleave the Ribosomal Sarcin-Ricin Loop",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/2h2akg3kh0qc2",
  "venue": "bioRxiv",
  "versions": []
}