{
  "abstract": "Type III CRISPR-Cas systems provide transcription-dependent immunity against mobile genetic elements, yet the mechanism underlying their DNA targeting remains unclear. Although the type III effector Cas10-Csm functions as a single-stranded DNase in vitro, type III systems eliminate double-stranded DNA targets in vivo, suggesting that transcription generates critical DNA substrates. Here, we show that conserved RNA polymerase anti-backtracking factors, such as GreA, selectively inhibit DNA-targeting of type III immunity. GreA overexpression abolishes protection against both phages and conjugative plasmids, whereas mutations that disrupt GreA anti-backtracking activity eliminate this effect. In contrast, immunity mediated by the type II CRISPR-Cas system or the auxiliary type III RNase Csm6 remain unaffected, demonstrating that GreA specifically suppresses Cas10-dependent DNA interference. These findings identify RNA polymerase backtracking as a key determinant of Cas10-Csm activity and support a model in which arrested transcription complexes generate substrates for DNA degradation, opening up new anti-CRISPR strategies against type III.",
  "abstract_shown": true,
  "affiliations": [
    "University of Wisconsin-Madison"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "A. J. Hernandez Viera"
    },
    {
      "name": "N. R. Gross"
    },
    {
      "name": "P. Q. Tran"
    },
    {
      "name": "O. Shahin"
    },
    {
      "name": "J. C. Kosmopoulos"
    },
    {
      "name": "K. Anantharaman"
    },
    {
      "affs": [
        0
      ],
      "name": "C. Y. Mo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5shjatkvpyxyh.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.04.764256",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764256v1.full",
  "id": "5shjatkvpyxyh",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764256v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "microbiology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764256v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5shjatkvpyxyh.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T12:20:40Z",
      "native_id": "10.64898/2026.11.04.764256",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764256v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "RNA Polymerase Backtracking Promotes Type III-A CRISPR DNA Targeting",
  "title_text": "RNA Polymerase Backtracking Promotes Type III-A CRISPR DNA Targeting",
  "type": "preprint",
  "updated_at": "2026-11-07T00:20:50Z",
  "url": "https://research.draconitic.com/paper/5shjatkvpyxyh",
  "venue": "bioRxiv",
  "versions": []
}