{
  "abstract": "The type six secretion system (T6SS) is a highly studied, versatile bacterial nanoweapon that is important in bacterial pathogenesis and evolution. Despite extensive study, its prevalence remains poorly quantified. Analyzing 35,467 representative genomes, we find that approximately 41% of genomes in the average well-sampled Gram-negative genus (more than 30 sampled genomes) encode a T6SS. Further, we show that the distribution of the T6SS is patchy at all taxonomic levels. The uneven distribution we found is consistent with context-dependent selection, repeated evolutionary loss, or greater evolutionary lability. Our dataset provides a foundation for studying the drivers of T6SS distribution, and our pipeline enables similar surveys of other secretion systems, gene clusters, and multi-protein complexes across bacteria.",
  "abstract_shown": true,
  "affiliations": [
    "Georgia Institute of Technology"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "name": "C. Zhang"
    },
    {
      "name": "H. Hassler"
    },
    {
      "name": "W. Ratcliff"
    },
    {
      "affs": [
        0
      ],
      "name": "L. Speare"
    },
    {
      "name": "B. K. Hammer"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dwyar89f9v30k.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.07.764895",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.07.764895v1.full",
  "id": "dwyar89f9v30k",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.07.764895v1",
  "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/10.64898/2026.11.07.764895v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dwyar89f9v30k.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T00:30:16Z",
      "native_id": "10.64898/2026.11.07.764895",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.07.764895v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "41% of Gram-negative bacteria encode a Type Six Secretion System",
  "title_text": "41% of Gram-negative bacteria encode a Type Six Secretion System",
  "type": "preprint",
  "updated_at": "2026-11-10T00:30:16Z",
  "url": "https://research.draconitic.com/paper/dwyar89f9v30k",
  "venue": "bioRxiv",
  "versions": []
}