{
  "abstract": "In linear polysomes, excluded-volume interactions among ribosomes can induce dimensional reduction of mRNA. Yet linear architectures allow steric stress to relax at open ends-- limiting how strongly crowding can remodel the mRNA's structure and dynamics. Using coarse-grained molecular-dynamics simulations, we compare circular and linear polysomes over a range of ribosome densities. Circular closure selects a predominantly quasi-planar global conformational ensemble, as indicated by a shape dimensionality dshape {approx} 2 over a range of ribosome densities. Crucially, circular topology and ribosome crowding act cooperatively to suppress structural fluctuations. While closure alone or linear crowding reduces relative global size fluctuations ({Delta}Rg/Rg) only to {approx} 0.16, their combined effect drives this fluctuation down to {approx} 0.07. Within this stabilized architecture, increasing ribosome density drives a distinct in-plane reorganization: the ring becomes more isotropic, global size fluctuations are strongly suppressed, and the scaling exponent increases toward {nu} [~=] 0.74 - 0.77, consistent with two-dimensional self-avoiding walk-like value over the accessible finite-size window, 1000 [≤] N [≤] 4969. Closure shortens the radius-of-gyration decorrelation time of circular polysomes by 40-fold relative to matched linear systems, reflecting the topological elimination of free ends. Within this closureselected ensemble, ribosome crowding further reduces the decorrelation time by up to 20% at the highest density. A fluctuation-informed crossover model links the density dependence of the global scaling exponent to inter-ribosomal subchain statistics. These results distinguish the geometric role of circular closure from the density-dependent steric response that it enables, revealing a confined yet dynamically responsive conformational regime for circular polysomes.",
  "abstract_shown": true,
  "affiliations": [
    "Spanish National Research Council CSIC-ICMAB"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "name": "H. Kobayashi"
    },
    {
      "affs": [
        0
      ],
      "name": "H. V. Guzman"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dyeh8nfmcg0j8.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.08.31.748270",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748270v1.full",
  "id": "dyeh8nfmcg0j8",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748270v1",
  "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",
      "biophysics"
    ],
    [
      "openalex",
      "1312|RNA and protein synthesis mechanisms"
    ]
  ],
  "openalex": "W7204937108",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748270v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dyeh8nfmcg0j8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:43Z",
      "native_id": "10.64898/2026.08.31.748270",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748270v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "biorxiv:biophysics",
      "subfield": "biophysics"
    }
  ],
  "title": "Topological Closure Drives Structural Stabilization and Fast Cooperative Dynamics in Crowded Circular Polysomes",
  "title_text": "Topological Closure Drives Structural Stabilization and Fast Cooperative Dynamics in Crowded Circular Polysomes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:43Z",
  "url": "https://research.draconitic.com/paper/dyeh8nfmcg0j8",
  "venue": "bioRxiv",
  "versions": []
}