{
  "abstract": "The LOV2 domain of Avena sativa phototropin 1 is widely used to control proteins with light, but how its signal reaches a fused effector has not been visualized. We followed photoactivatable Rac1 by time-resolved serial crystallography at room temperature. Within 350 {micro}s, a fifth of the photosensors form the flavin-cysteine adduct and tilt as a rigid body on Rac1 about an axis through the domain interface, while the J helix stays docked and Rac1 keeps GTP and dark-state switches up to 1.85 ms. Dark crystals contain a variable GDP-bound sub-population, so light data must be referenced to interleaved dark frames. In this sub-population, switch I is only partially open, held at a Ca2+ ion that bridges LOV2 and Rac1, a conformation that can persist in simulations without the lattice. The photosensor thus first acts on Rac1 at the interface that also holds switch I in the GDP-bound state.",
  "abstract_shown": true,
  "affiliations": [
    "Dioscuri Centre for Structural Dynamics of Receptors, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 19,
  "authors": [
    {
      "name": "M. Pachota"
    },
    {
      "name": "M. K. Shankar"
    },
    {
      "name": "M. Wisniewska"
    },
    {
      "name": "A. Koczurowska"
    },
    {
      "name": "C. M. Casadei"
    },
    {
      "name": "A. Solecka"
    },
    {
      "name": "S. M. Kapetanaki"
    },
    {
      "name": "B. Olasz"
    },
    {
      "name": "L. Lopes Cavalcante"
    },
    {
      "name": "R. Ke"
    },
    {
      "name": "D. Lang"
    },
    {
      "name": "M. Bjelcic"
    },
    {
      "name": "A. Asghar"
    },
    {
      "name": "M. Milas"
    },
    {
      "name": "T. Ursby"
    },
    {
      "name": "M. Chenchiliyan"
    },
    {
      "name": "J. Nan"
    },
    {
      "name": "E. Rosta"
    },
    {
      "affs": [
        0
      ],
      "name": "P. Nogly"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fbb04rzs2c3wy.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.27.762334",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.10.27.762334v1.full",
  "id": "fbb04rzs2c3wy",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.10.27.762334v1",
  "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",
      "biophysics"
    ],
    [
      "openalex",
      "1312|Protein Kinase Regulation and GTPase Signaling"
    ]
  ],
  "openalex": "W7224079464",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.10.27.762334v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fbb04rzs2c3wy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:18Z",
      "native_id": "10.64898/2026.10.27.762334",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.10.27.762334v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "biorxiv:biophysics",
      "subfield": "biophysics"
    }
  ],
  "title": "Photoactivatable Rac1: a photosensor tilt by time-resolved crystallography and a partially open switch I when GDP-bound",
  "title_text": "Photoactivatable Rac1: a photosensor tilt by time-resolved crystallography and a partially open switch I when GDP-bound",
  "type": "preprint",
  "updated_at": "2026-10-30T12:30:18Z",
  "url": "https://research.draconitic.com/paper/fbb04rzs2c3wy",
  "venue": "bioRxiv",
  "versions": []
}