{
  "abstract": "Base editors act on the DNA strand displaced within an R-loop, and the set of positions they convert, the activity window, has been engineered for a decade on the assumption that linker length and attachment geometry determine it. We built a geometric model that predicts where a tethered deaminase acts from linker statistics, steric exclusion, and R-loop geometry alone; fitted three parameters to two previously reported profiles, held them fixed, and scored predictions against 50 architectures from seven studies, with each substrate coordinate withheld. Varying the contour length by a factor of 16 does not shift the predicted window at all, whereas changing the attachment site does: across 185 buildable single-linker designs at thirteen attachment sites, the predicted peak never leaves protospacer positions 3 to 12, positions 1, 2 and 13 to 20 are reached by no design, and transfer to Cas12a fails by five to six nucleotides in a way that localizes to the fusion junction rather than to reach, sterics or substrate. Tether geometry, therefore, bounds where a fused deaminase can act without predicting where it does so, making attachment site rather than linker length the effective design variable.",
  "abstract_shown": true,
  "affiliations": [
    "School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India."
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "name": "A. A. Mahaboob Ali"
    },
    {
      "affs": [
        0
      ],
      "name": "E. J. R. Nelson"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3fg3m8nsy79sc.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.16.751980",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.16.751980v1.full",
  "id": "3fg3m8nsy79sc",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.16.751980v1",
  "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",
      "synthetic biology"
    ],
    [
      "openalex",
      "1312|CRISPR and Genetic Engineering"
    ]
  ],
  "openalex": "W7213460351",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.16.751980v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3fg3m8nsy79sc.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:48Z",
      "native_id": "10.64898/2026.09.16.751980",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.16.751980v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:synthetic biology",
      "subfield": "systems-synthetic"
    }
  ],
  "title": "Attachment site, not linker length, bounds tethered base editor windows",
  "title_text": "Attachment site, not linker length, bounds tethered base editor windows",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:48Z",
  "url": "https://research.draconitic.com/paper/3fg3m8nsy79sc",
  "venue": "bioRxiv",
  "versions": []
}